Treaty scrutiny in Parliament: Lords International Agreements Committee report

Approximate read time: 15 minutes

The House of Lords is scheduled to debate the following motion on 16 March 2026:

Lord Goldsmith (Labour) to move that this House takes note of the Report from the International Agreements Committee ‘Treaty scrutiny in Westminster: Addressing the accountability gap’ (10th Report, HL Paper 168)

1. Scrutiny of treaties in the UK Parliament

Treaties are international agreements concluded in writing between nation states which create rights and obligations in international law. In the UK, treaty-making is a function of the government under the royal prerogative.^[1] However, Parliament does have a role in the process of ratification. Since 1924 there has been a convention (known as the Ponsonby rule) that, once signed, treaties are laid before Parliament for 21 days before they can be ratified.^[2] In 2010, this convention was placed on a statutory footing in part 2 of the Constitutional Reform and Governance Act 2010 (CRAG Act 2010).

The CRAG Act 2010 contains requirements about what must happen in UK law before the government can ratify a treaty. The usual process, as set out in section 20(1), is that a treaty cannot be ratified unless:

• a minister has laid a copy before Parliament;
• the treaty has been published in a way that the minister thinks appropriate; and
• a period of 21 sitting days has elapsed since the day after the treaty was laid before Parliament, without either House resolving that it should not be ratified.

Should the Commons resolve against ratification, the minister may lay a statement indicating that the minister is of the opinion that the treaty should nevertheless be ratified and explaining why. A second period of 21 sitting days is then triggered, during which the Commons may resolve again against ratification. Similarly, the minister may then lay another statement. In such a way the Commons theoretically has the power to delay ratification indefinitely.

The House of Lords does not have this same power under the CRAG Act 2010. Should the Lords resolve against ratification and the Commons not resolve against ratification, then the treaty may be ratified through provisions under sections 20(7) and (8) if “a minister of the crown has laid before Parliament a statement indicating that the minister is of the opinion that the treaty should nevertheless be ratified and explaining why”.

While the CRAG Act 2010 gives the Commons, at least in theory, the ability to delay indefinitely the ratification of a treaty, the act does not require either House to debate or vote on or actively approve a treaty before it can be ratified. The House of Lords Constitution Committee has noted that the Commons can resolve against ratification repeatedly “only if the government makes time for debates and votes to take place”.^[3] The committee recommended that if a treaty scrutiny committee recommended a debate on a treaty, then the government should commit to providing time for it within the 21-day period.^[4] In its response to the committee, the then government said that, subject to various constraints, if a debate under the CRAG Act 2010 was requested in this way it would “endeavour to ensure parliamentary time [was] found”.^[5] In its September 2025 report on treaty scrutiny in Parliament, the House of Lords International Agreements Committee stated that in practice the House of Commons has never voted against the ratification of a treaty and the House of Lords has only done so once.^[6]

Section 20 of the CRAG Act 2010 can be disapplied using provisions of section 22 “if a minister of the crown is of the opinion that, exceptionally, the treaty should be ratified without the requirements of that section having been met”. Section 22(3) requires the minister to explain in a statement why they are of that opinion. However, this procedure cannot be used if either House has already resolved against the treaty being ratified. The 21-day period can also be extended by the government under section 21.

In addition to procedures under the CRAG Act 2010, Parliament may need to pass legislation to implement an international agreement in domestic UK law. The UK is a dualist state. This means that international treaties do not automatically become part of its domestic law. In instances where agreements (or parts thereof) need to be implemented in domestic law, Parliament will need to pass legislation. Foreign, Commonwealth and Development Office (FCDO) guidance on treaties says that if domestic legislation is needed to enable the UK to give effect to its obligations under a treaty, the legislation should be in place before the treaty comes into force, so that the two can come into operation at the same time.^[7] The FCDO therefore usually insists that any necessary UK legislation is in place before a treaty is ratified or acceded to.

Parliamentary committees in both Houses may also report on international treaties. For example, the House of Lords International Agreements Committee scrutinises all treaties subject to ratification that are laid before Parliament under the CRAG Act 2010. It also considers ongoing negotiations.^[8] The only exception is that treaties between the UK and the EU/EEA are scrutinised by the House of Lords European Affairs Committee.^[9] The International Agreements Committee has noted that there is no equivalent process in the Commons, but has stated that “sometimes the relevant policy committee will report on a treaty”.^[10] For example, the House of Commons Business and Trade Committee has reported on free trade agreements such as the UK-India Comprehensive Economic and Trade Agreement.^[11]

Previous parliamentary committee reports have expressed concern about the level of parliamentary scrutiny of international treaties. For example, the House of Lords Constitution Committee considered the CRAG Act 2010 in a report published in April 2019.^[12] Amongst its conclusions, the committee argued that the act’s provisions for enabling parliamentary scrutiny of treaties were “limited and flawed” and that reform was needed to allow for effective scrutiny.^[13] In its response to the report, the then government said that the CRAG Act 2010 remained a “viable legal framework for scrutiny”, but it agreed that “improvements can be made to the operation of the scrutiny mechanisms and processes within that framework, and that information provision between the executive and Parliament can also be improved”.^[14]

2. Lords International Agreements Committee report

The House of Lords International Agreements Committee has argued that the UK’s exit from the EU highlighted the issue of the parliamentary scrutiny of treaties, particularly with regard to the concluding of free trade agreements. This had been within the competence of the EU whilst the UK was a member state. The committee argued that this “shone a light on the weakness of the Westminster treaty scrutiny process in comparison to the powers exercised by the European Parliament over EU-negotiated treaties”.^[15] It said that since 2019 there had been six enquiries by five different parliamentary committees on aspects of the scrutiny process.^[16]

The House of Lords International Agreements Committee’s most recent report on this subject, ‘Treaty scrutiny in Westminster: Addressing the accountability gap’, was published on 11 September 2025. The subject was chosen to coincide with the committee’s five year anniversary. The report considered:

• how the treaty scrutiny process has operated during the lifetime of the committee
• what further practical and operational changes could be implemented to make scrutiny under the current legislative framework more effective
• whether legislative reform is needed
• whether the government’s objections to reform are valid

The committee concluded that the CRAG Act 2010’s framework was a “weak and insufficient mechanism for securing meaningful accountability to Parliament”.^[17] It argued that the statutory time limit for scrutiny was not long enough to allow for an in-depth evidenced based review of what it described as significant treaties. The committee described the CRAG Act 2010’s provisions as a “useful adjustment of traditional executive autonomy” but argued that it “tilts the process too far in the government’s favour and allows it too much discretion to act in ways which limit detailed scrutiny”.

The committee argued that legislation should be reformed to provide for parliamentary approval of significant treaties and to address:

• the time for scrutiny of such treaties,
• the scope of the scrutiny process
• the approach to trade agreements
• the role of the devolved parliaments

The committee came to a wide range of conclusions and made a number of recommendations in its report.^[18] These included:

• Scrutiny of implementing legislation is no substitute for treaty scrutiny. Parliament should have the opportunity to consider the treaty as a whole so it can consider the policy reasons for the UK becoming a party. Treaty scrutiny should precede the presentation to Parliament of implementing legislation.^[19]
• We regret that the government has refused to extend the scrutiny period in cases where it accepts there is a strong public interest in the treaty and there is no urgency to ratify. We can see no justification for the government’s refusal to set out the factors it takes into account when considering extension requests. This would not stop decisions being made on a case-by-case basis but it would provide greater predictability as to the likely response. It would also give Parliament and the public greater confidence that such requests are not being refused simply for reasons of political expediency.^[20]
• The government should be ready to share with Parliament on request by this committee (or another parliamentary committee engaged in treaty scrutiny) the texts of significant new treaties in advance of their laying under the CRAG Act [2010]. The committee should be able to share these texts, if necessary, with prospective witnesses. The sharing of FTA [free trade agreement] texts at the signature stage shows that there can be no impediment of principle to this approach. If the government considers that there are well-founded policy reasons for not sharing the signed text of a treaty with Parliament before it is formally laid, it should explain these in writing to the committee.^[21]
• The FCDO should work with the committee secretariat to design a better process for giving the committee a more accurate picture of the pipeline of forthcoming treaties. It should act as a hub to coordinate with other Whitehall departments to ensure that it has the necessary information.^[22]
• In its response to the PACAC [House of Commons Public Administration and Constitutional Affairs Committee] report in 2024 the government said that it “welcomes any efforts to ensure the UK has an efficient and sustainable process of scrutiny to support transparency and accountability in its treatymaking.” Codifying in a single document all the commitments which the government has made concerning operation of the treaty scrutiny process would be a concrete step to meeting this objective. We call on the government to commit to concluding such a document within the next 12 months and to engage constructively with us on its scope and content.^[23]

3. Government response

The government responded to the committee’s report in December 2025.^[24]

The government said it respected and valued the work of the committee. However, it saw some difficulties in the committee’s proposals, but it was also “keen to work with the committee to help to mitigate or resolve, so far as possible, the issues which the committee has raised”.^[25] It said it believed that progress could be made through the government and the committee “engaging in more dialogue and by working together to improve working practices”. This included:

• working to ensure that the committee has an accurate picture of the pipeline of forthcoming treaties to be laid
• updating the template and guidance on explanatory memoranda to clarify the type of information which would be helpful for scrutiny
• updating guidance for departments on engagement with Parliament, including on providing information and briefing in advance of laying
• exploring options to ensure that the committee is appropriately sighted on treaty actions which may be relevant to its mandate
• reviewing guidance to ensure that it promotes and facilitates implementation of existing commitments^[26]

However, the government said it did not believe there was a strong case “for more fundamental reform of parliamentary scrutiny, including statutory changes to the period available for scrutiny or the role of Parliament in approving (or otherwise) significant treaties”. The government said it believed that the provisions of the CRAG Act 2010 continued to strike a good balance between the government’s role in making treaties and Parliament’s scrutiny role. Although it also said that it would discuss with the committee how working practices around the legislation could be improved:

However, in this area as well, the government is willing to discuss with the committee how to improve working practices to ensure that the balance of powers in the CRAG Act [2010] enables Parliament to give proper scrutiny to treaties, particularly significant treaties.^[27]

The government also responded to the committee’s specific conclusions and recommendations. For example, in response to the committee’s concern about factors the government takes into account when considering extension requests, the government said:

The government acknowledges the committee’s concerns about workload, and will work closely with the committee to manage the pipeline of treaties being laid so they are more evenly spread and avoid pressure points. Where extensions are requested, the government considers it important to take decisions on a case-by-case basis in light of operational needs and other factors; and the government needs to retain the ability to decide not to extend the period in any case.^[28]

The government said when considering an extension to the scrutiny period under section 21 of the CRAG Act 2010, it considers the following factors:

• any factors raised by the committee as to why, exceptionally, the 21-day scrutiny period should be extended, such as the nature of the treaty
• the length of the extension requested by the committee
• the overall time available to the committee for the scrutiny of the treaty, including the committee’s ability to prepare for formal scrutiny of the treaty
• the effect of an extension on the handling of the treaty, including any potential effect on the implementation and bringing into force of the treaty
• any other factors that the minister considers relevant to the particular treaty^[29]

4. Read more

• House of Commons Library, ‘Treaty-making and parliamentary scrutiny: recent developments’, 23 October 2024
• House of Commons Public Administration and Constitutional Affairs Committee, ‘Parliamentary scrutiny of international agreements in the 21st century’, 29 January 2024, HC 204 of session 2023–24 and ‘Government response’, 18 April 2024
• House of Commons International Trade Committee, ‘UK trade negotiations: Parliamentary scrutiny of free trade agreements’, 27 October 2022, HC 815 of session 2022–23 and ‘Government response’, 26 January 2023
• House of Lords International Agreements Committee, ‘Working practices: One year on’, 17 September 2021, HL Paper 75 of session 2021–22 and ‘Government response’, 8 February 2022. See also: House of Lords Library, ‘International Agreements Committee report on improving the framework for the parliamentary scrutiny of treaties’, 16 May 2022
• House of Lords European Union Committee, ‘Treaty scrutiny: Working practices’, 10 July 2020, HL Paper 97 of session 2019–21 and ‘Government response’, September 2020. See also: House of Lords Library, ‘Parliamentary scrutiny of treaties: Debate on committee reports’, 19 August 2020
• House of Lords European Union Committee, Scrutiny of international agreements: Lessons learned, 27 June 2019, HL Paper 387 of session 2017–19. See also: House of Lords Library, ‘Parliamentary scrutiny of treaties: Debate on committee reports’, 19 August 2020
• House of Lords Constitution Committee, ‘Parliamentary scrutiny of treaties’, 30 April 2019, HL Paper 345 of session 2017–19 and ‘Government response’, July 2019. See also: House of Lords Library, ‘Parliamentary scrutiny of treaties: Debate on committee reports’, 19 August 2020
• Joint Committee on Human Rights, ‘Human rights protections in international agreements’, 12 March 2019, HL Paper 310 of session 2017–19

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Photo by N R on Unsplash

Section 1 of this briefing was updated on 11 March 2026 to note the role of the House of Lords European Affairs Committee.