Parliament has three functions in the Brexit process:

• to play its role in the international treaty-making and -unmaking that will be involved;

• to scrutinise the executive’s handling of the process; and

• to put in place the domestic law needed or desired to effect the UK’s EU withdrawal.

These three functions will frame the Hansard Society’s work on Brexit this year and beyond. In 2017, the three will come into focus roughly sequentially. Parliament's treaty role will be defined by the prime minister’s commitment in her speech to give both houses a vote on the UK-EU exit agreement, then the Supreme Court’s Article 50 ruling on January 24, and then the passage of any Article 50 bill by the end of March. As regards scrutiny, much work is already underway, particularly in select committees, but - especially now that the government appears to have resiled from a commitment to publish a pre-Article 50 document - the scope of Parliament's Brexit scrutiny is likely to be at the forefront of the arguments surrounding any Article 50 bill after the Supreme Court rules. Once Article 50 is triggered in late March, parliamentary scrutiny will then be put to the test as the Brexit negotiations get underway. The domestic legislation involved in Brexit will come into focus with the Great Repeal Bill, which will be included in the Queen’s Speech at the start of the new parliamentary session in May.

Combined, the way in which Parliament carries out these three functions could take it towards one or other of two scenarios:

Brexit results in an empowered executive. The government’s customary advantage over Parliament in international affairs is bolstered by the political imperative to be seen to be delivering the referendum result, and the practical urgency of getting a vast amount done quickly. In the face of Brexit’s scale and complexity, Parliament fails to rise to the challenge and has little impact on the process, thanks to a lack of time and resources, often limited understanding of EU issues, enduring post-referendum political divisions, poor coordination among the many parliamentary actors involved, distraction by other issues and the political effects of extra-parliamentary campaigning against any perceived obstruction to implementation of the referendum result.

Brexit enhances Parliament's influence and standing. The unexpected and unprecedented nature of Brexit proves to be a leveller between the executive and legislature. Brexit’s pan-UK but territorially differentiated nature spurs the building of stronger relationships between Westminster and the devolved legislatures. Parliament takes advantage of the post-referendum space for policy development and unconventional coalition-building, the government’s internal differences and small Commons majority, high public interest, and the precedent of a parliamentary EU scrutiny system that has sometimes been capable of holding the government up, to become a key site for information-gathering and dissemination, policy generation, consensus-building and decision-making.

The Hansard Society is interested in which of these scenarios plays out, and why.

We think it matters, for three reasons.

First, Parliament could make a difference to Brexit’s policy content – the future trade terms between the UK and the EU, or the post-Brexit policies that the UK adopts in agriculture, regional development, higher education or immigration. This will depend on parliamentarians exploiting the opportunities open to them.

Second, the handling of Brexit, across Parliament's three functions, will create processes and precedents that could endure into - or at least shape - the post-Brexit era. For example, international treaty-making will be a more prominent and possibly more extensive element of UK foreign policy once the UK is able to negotiate international trade agreements on its own. The Supreme Court ruling and the treatment of any UK-EU Brexit-related agreement or agreements will set frameworks and precedents for Parliament's role in this respect. The House of Lords EU Committee has already suggested, in its October 2016 report on Brexit scrutiny, that any system established to give Parliament some control of the Brexit negotiations could become the template for the handling of any post-Brexit international trade deals.

Similarly, the Hansard Society has already argued that the likely volume and importance of Brexit-related delegated legislation ought finally to be the spur to long-overdue reform of Parliament's scrutiny procedures for this class of law, primarily in the House of Commons. The prospect of the Great Repeal Bill has prompted the House of Lords Constitution Committee to bring forward the delegated powers element of its inquiry into the legislative process, and the House of Commons Procedure Committee might also look into delegated legislation. Relations between the two Houses, and between Westminster and the devolved legislatures, are other areas where the Brexit process could have a lasting impact; while, from among select committee chairs, who is seen to have had a ‘good Brexit’ could help shape the select committee system for the post-Brexit age.

Third, as indicated above, Parliament's constitutional and political role is at stake. Parliament - not just individual parliamentarians - needs to have a ‘good Brexit’. Get it wrong (our first scenario above), and Parliament's weaknesses could be among the relatively few things left unchanged by Brexit. Get it right - ‘make a success of it’ - and a reformed legislature could enter the post-Brexit era better connected with citizens and a more equal player in the UK’s democratic politics. An early indicator of the possible direction of travel will come with the Hansard Society’s latest annual Audit of Political Engagement, the first results of which are just in…

(1) Winston Churchill, ‘The duties of a Member of Parliament’, Parliamentary Affairs, Vol. VIII, No 3, Summer 1955. The extract was cited by the Select Committee on Modernisation of the House of Commons in its 2007 report Revitalising the Chamber: the role of the back bench Member (HC 337), the last time a Commons body considered this issue.

Fowler, B. (2017), Why Parliament needs a 'good Brexit', (Hansard Society: London)