Today sees the publication of a new book by the Unit’s Meg Russell and Lisa James, The Parliamentary Battle over Brexit. Here the authors summarise some of its key findings about why parliament was drawn into such controversy over the implementation of Brexit. They reflect on what these events teach us about our constitution, as well as what may need to change in order to avoid repeating such problems, and to mend the damage done.

The UK’s arguments over what became known as Brexit began long before the June 2016 referendum, and continued with increasing bitterness afterwards. Parliament was often central, both as a venue for such arguments, and in terms of disputes about its proper role. It and its members frequently faced criticism and blame. Our new book, published today, charts The Parliamentary Battle over Brexit, from the early pressures for a referendum, through disputes about the triggering of Article 50 and control of the House of Commons agenda, the repeated defeats of Theresa May’s deal, and Boris Johnson’s unlawful parliamentary prorogation, to the UK’s eventual departure from the EU following his deal. The book charts what happened, but also asks what went wrong and whether things could have been handled differently. It reflects on what these events teach us about the functioning of our constitution, and what if anything might need to change.

The book includes a wealth of detail about key political moments, and the roles of different individuals and groups. Here we focus on some of the bigger questions about the lasting legacy of the battles over Brexit for the culture and institutions of UK politics, and particularly for the place of parliament itself. A fuller version of this analysis appears in the final chapter of the book.

Referendums and public participation

The referendum of 23 June 2016 was only the third ever such UK-wide vote (the first being on European Community membership in 1975, and the second in 2011 on changing the House of Commons voting system). The handling of the referendum was the single biggest error of the Brexit process, from which many other difficulties flowed.

Unlike the 2011 referendum, which was underpinned by legislation setting out the detail of the proposed new voting system, no clear prospectus was offered to the voters for Brexit. Prime Minister David Cameron hoped to use the vote – described disapprovingly by the House of Commons Public Administration and Constitutional Affairs Committee as a ‘bluff call’ referendum – to make the question of Brexit go away. Parliament never debated the substance of the question, the government did not detail the options, and civil servants were forbidden from preparing for a Leave vote. Leave campaigners argued at the level of principle, rather than on a specific plan. As one Brexit-supporting interviewee told us, ‘it was only [after the referendum] that different types of Brexit started coming to the fore. Soft Brexit and hard Brexit had never been canvassed before the referendum; the expressions were coined afterwards’. Issues that would soon come to dominate the agenda, such as membership of the Customs Union or Single Market, and crucially the Northern Ireland border, were barely mentioned during the campaign. This left the government – and parliament – in a very difficult position. The different options for Brexit had to be established only after the vote had taken place, and on this the voters had conveyed no clear instruction.