Following an evidence session to the Public Administration and Constitutional Affairs Committee (PACAC) on whether Parliament should have a role in scrutinising international treaties, PLP Head of Research Arabella Lang sets out three key reforms needed to improve treaty scrutiny and why they are needed now more than ever.


Treaty-making is a job for the executive, but this doesn’t mean Parliament should be shut out. Yesterday we told PACAC that prerogative treaty powers should be balanced against other important constitutional principles of parliamentary sovereignty, parliamentary accountability and the rule of law. 

Treaties matter. Many modern treaties affect everyone: the growth of the global economy and the impact of global issues means they now cover areas like data rights, domestic violence, social security, and employment rights. Until recently those were matters for domestic law alone, so Parliament could determine the balance between competing interests. But now, our domestic law and regulation in these areas is constrained by treaty commitments, which have little or no democratic input at the point where it could make a difference. The effect is that more law is made by the executive alone. 

‘Good parliamentary scrutiny is in the Government’s interests’

These are long-standing issues that have been illuminated by Brexit. Leaving the EU brought control of important treaty areas like trade and the environment back to UK, but resulted in less democratic scrutiny of them because not all the scrutiny powers of the European Parliament and the UK’s European scrutiny committees were transferred. This has shone a light on an existing accountability gap and gives us an opportunity to address it. 

Good parliamentary scrutiny is in the Government’s interests. If done properly, it would generate more expert input and make better treaties; create deeper consent to treaties that can long outlive one administration; and establish greater trust with partners. 

The three most important reforms to achieve this are: 

  • A new requirement for Commons assent for important treaties, not only to allow assent to be given or withheld but also to stimulate scrutiny beforehand.
  • A new politically-binding concordat between Parliament and the Government setting out their respective roles on treaties at different points in the process, to avoid any rowing back on commitments
  • Better information and resources to support scrutiny, such as: independent assessment of treaties against UK domestic standards; compulsory assessments of the impact on groups with protected characteristics and those that experience disadvantage because of their socio-economic status; and appointing treaty scrutiny experts in the House of Commons to advise, support and help coordinate its work on treaties.  

Given the impact of treaties on our everyday lives, striking the right balance between Parliament and the executive must become a priority if we are to ensure that treaties are made fairly, and there is real accountability if they are not. But this will take resource and commitment: political will is what will make it happen.