Documents to download


International treaties matter to everyone. They can be as important as domestic legislation – sometimes more so – and are an increasing part of UK Government activity, particularly in areas previously handled for the UK by the EU such as trade and fisheries.

In response, Parliament has increased committees’ treaty scrutiny, and the Government has made some commitments to support scrutiny of trade treaties. However, treaty scrutiny generally remains under-developed and under-resourced even compared to scrutiny of delegated legislation, and Parliament’s formal involvement is still limited.

Proponents of change argue that giving Parliament a bigger role could help the government make better treaties and would increase the democratic legitimacy of this area of government law-making. The Government argues that such changes would interfere with its treaty making powers and its responsibility for conducting foreign policy.

The government makes treaties…

The starting point is that governments make treaties. The UK Government is responsible for negotiating, signing, ratifying, amending and withdrawing from all international treaties involving the UK, under its prerogative powers, and it is the UK Government that is bound by them under international law.

It is also responsible for providing information about treaties. It has made some commitments to increased provisions here, but has rejected proposals for a presumption of transparency.

…but Parliament has some roles

Parliament does have several treaty roles. But since the UK vote to leave the EU, there has been an increased focus on the perceived limitations of Parliament’s role in relation to international treaties.

Legislation may be needed

The main formal limits on the Government’s treaty powers are that: (1) treaties cannot automatically change domestic law or rights in the UK; and (2) they cannot make major changes to the UK’s constitutional arrangements without Parliamentary authority.

Parliament (and/or the devolved legislatures) is therefore involved if domestic law needs to be changed in order to implement a treaty. But implementing legislation is not always necessary. Where legislation is needed, its provisions will be predetermined by the contents of the treaty. And increasingly this legislation will be only secondary (government-made) rather than primary (parliament-made).

The Commons could delay ratification

Separately from legislating for treaties, since 2010 the Commons has had a statutory opportunity to delay the Government’s ratification of treaties. But to do so it must find an opportunity to vote against ratifying a signed treaty, during a short statutory period.

Under Part 2 of the Constitutional Reform and Governance Act 2010 (CRAG), the government cannot ratify a treaty unless it has first laid the signed treaty before Parliament (along with an Explanatory Memorandum), for 21 sitting days. This gave statutory form to part of a 1920s constitutional convention on treaties, known as the Ponsonby Rule.

The CRAG Act also for the first time gave the House of Commons a new power: if during that statutory pause it passes a resolution that a treaty should not be ratified, another 21-sitting-day delay to ratification is triggered – and this process may be repeated. A Lords resolution against ratification does not have this effect.

Neither House has yet passed a resolution against ratification of a treaty under these provisions.

Enhanced arrangements for free trade agreements

The Government has agreed some enhanced arrangements for scrutiny and debate of free trade agreements (FTAs), following the UK’s departure from the EU. These include consultation before negotiations begin, publishing the outline negotiating mandate, regular updates on the negotiations, and extra time for committee scrutiny of the finalised agreements.

But it has shown no sign of extending these to non-trade treaties, or to any post-Brexit treaties with the EU, and has repeatedly rejected proposals to require parliamentary consent for any treaties.

Exceptionally, Parliament may need to authorise treaty actions in advance

In its 2017 Miller judgment, the UK Supreme Court ruled that Parliament needed to legislate to authorise treaty actions in advance in two very specific and exceptional circumstances: where invoking a provision of the treaty amounted to a major change to UK constitutional arrangements, or where it would sever an existing source of domestic law and rights. It is unlikely that these circumstances will arise again outside the Brexit context.

Committee scrutiny

Committees in both the Commons and the Lords have significantly increased their treaty scrutiny work recently. The House of Lords has established a new, dedicated International Agreements Committee to consider all treaties, before, during and after ratification. The Commons International Trade Committee has also scrutinised Brexit-related trade agreements, such as the 2020 UK–Japan Comprehensive Economic Partnership Agreement.

The Joint Committee on Human Rights continues to sift and scrutinise human rights treaties and those with human rights considerations. Along with many other committees, it has made numerous recommendations about how to improve parliamentary scrutiny of treaties.

Some other committees are also beginning to be involved, for instance the Commons Environment, Food and Rural Affairs Committee, whose chair used the new ‘guesting provisions’ to join the International Trade Committee for several meetings.

However, there are still significant challenges for committees in getting the information they need, and in reporting on treaties in the time available.

Limits and exceptions to Parliament’s role

Although CRAG gave Parliament a statutory role on treaties, it is limited in both depth and breadth, and has resulted in little practical difference.

Limited depth

CRAG does not require Parliamentary approval of treaties. Nor does it require scrutiny, debates or votes on treaties, or even create any triggers or mechanisms for them. Opportunities for debate on the floor of the House of Commons depend, to a significant extent, on the willingness of the Government to facilitate them because it controls most of that time.

Parliament has no formal input while the Government is negotiating treaties, which is the stage when changes could be made. In some other countries like Norway, for example, major foreign policy decisions are discussed confidentially with parliamentary committees in advance. Under the CRAG Act, Parliament can only oppose (or tacitly accept) a concluded treaty in full, as signed treaties cannot be unilaterally amended.

Furthermore, the CRAG period is too short for a typical committee inquiry, and there is no link between scrutiny of treaties and of their implementing legislation.

Limited breadth

The CRAG Act covers only some treaties, and no other international arrangements such as Memorandums of Understanding, which do not even have to be listed let alone published.

Nor does it cover most treaty amendments, or any treaty withdrawal, derogations or decisions made under a treaty.

Furthermore, the Government may exempt a treaty from the CRAG provisions in ‘exceptional cases’, or avoid them altogether through a treaty’s implementing legislation.

Brexit negotiations and agreements

The negotiations for the UK’s withdrawal from the EU exposed the long-standing challenges of parliamentary treaty scrutiny.

Many parliamentarians and committees wanted Parliament to be able to play a constructive part in helping the Government secure the best outcome for the UK. Recurring challenges included getting information from the Government, securing regular ministerial appearances, the quality of government responses, committee coordination and overlaps.

Withdrawal Agreement

Amid much controversy, the EU (Withdrawal) Act 2018 was amended against the Government’s wishes to include a ‘meaningful vote’ provision. This required parliamentary consent for the Government to ratify the Withdrawal Agreement with the EU. But after the December 2019 election this provision was repealed by the EU (Withdrawal Agreement) Act 2020, which also disapplied the CRAG treaty provisions for the Withdrawal Agreement.

Trade and Cooperation Agreement

Then in December 2020, the Government agreed the Trade and Cooperation Agreement (TCA) with the EU without the House of Commons having had a formal debate on the substance of the UK’s negotiating position. The implementing Bill was passed in one day, providing Parliament with very little time to scrutinise either the treaty or its implementing legislation.

‘Rollover’ agreements

Parliamentary committees published dozens of reports on Brexit-related matters, and also scrutinised the Brexit-related treaties with around 60 other countries. These ‘rollover’ agreements were intended largely to reproduce the effects of existing treaties between those countries and the EU that no longer applied to the UK after Brexit. They covered a wide range of topics in addition to Brexit.

Future scrutiny

Many committees have argued that the UK Parliament will still need to scrutinise the implementation of the Brexit treaties and any future negotiations with the EU, but no new structures or mechanisms have yet been introduced.

Devolved executives and legislatures

Treaty-making remains the exclusive responsibility of the UK Government. The devolved executives and legislatures therefore have little involvement in treaties, even though they are bound by them and may be responsible for applying them.

Note: this briefing paper replaces Commons Library Briefing Paper 5855, Parliament’s Role in Ratifying Treaties, 17 February 2017.

Documents to download

Related posts