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A new book – The Parliamentary Battle over Brexit – charts the dramatic story of Brexit in Parliament. Authors Meg Russell and Lisa James explore five key episodes.

  1. Some Remainers campaigned for a Brexit referendum

It is widely noted that David Cameron called the 2016 EU referendum on the assumption that Remain would win – and in an attempt to quell Eurosceptic dissent within his party. The associated failure to plan for a Leave outcome laid the ground for much of the turmoil of the Brexit years.

But Cameron was far from alone in hoping that holding a referendum might settle the divisive issue of Europe. He was initially subject to significant backbench pressures to stage a referendum. But some MPs who supported these efforts did not back Brexit, and indeed some later found themselves on the other side of the debate. Backbenchers were often responding to pressure from local voters and constituency associations. But some also, as one such interviewee put it, hoped that a decisive Remain victory might ‘lance a boil’ within the party.

This kind of optimism was not limited to the Conservative Party. Though Cameron’s predecessors as Conservative leader called for referendums on treaty change, the first mainstream party leader to propose an in-out referendum in this period was Liberal Democrat Vince Cable.

  1. Attempts to increase Parliament’s power over Brexit proved a ‘godsend’ for hard Brexiteers

Appeals to parliamentary sovereignty were a long-standing argument of Eurosceptics. But post-referendum, Parliament’s role in deciding the form of Brexit quickly became contentious.

Two key flashpoints illustrate. First, in the 2016-17 legal case brought by Gina Miller, the Supreme Court ruled that legislation was required to authorise the executive to trigger Article 50. In 2018, a statutory requirement for a meaningful vote in the House of Commons on the final Brexit deal was inserted into legislation by Dominic Grieve and his allies, against the government’s wishes.

Both initiatives were led by figures closely associated with the Remain cause, and both were opposed by Brexiteers, who characterised them as attempts to frustrate the referendum result. But in the end, Brexiteers benefited.

Two such interviewees independently described the Miller Supreme Court decision to us as a ‘godsend’; the court’s ruling that the Prime Minister needed legislative authorisation to trigger Article 50 locked her – and parliament more widely – into this decision, forestalling any subsequent attempt to revoke. The meaningful vote, meanwhile, would provide the means to block May’s Brexit deal.

  1. Brexiteers were key to the defeat of May’s deal

May’s deal suffered three heavy defeats in the House of Commons in early 2019 – with Leave supporters delivering the decisive blow. In the first vote, more Leavers opposed May’s deal than supported it. Most obviously in the third and closest vote, Brexiteer votes were pivotal. Of the 34 Conservative rebels, 28 – the so-called ‘Spartans’ – were Brexiteers associated with the hardline European Research Group (ERG). Had they and the Brexit-supporting Democratic Unionist Party (DUP) supported May’s deal, it would have passed.

May’s Brexiteer opponents also hindered her deal passing in this final tight vote in another way. Throughout this period, the Labour Party had faced a strategic dilemma. Working with May’s government might have provided leverage over the final Brexit outcome; but many Labour MPs had strongly Remain constituencies, and personally opposed Brexit.

Meanwhile others had voters who had tilted to Leave. This latter group in particular were tempted to support May’s deal on the third occasion. But by then, she was under such pressure from her internal critics that, in the words of one Labour interviewee ‘the danger is you could vote for it, and then it’d be overturned three days later by Boris Johnson becoming Prime Minister and doing something mad’. Despite major efforts from Downing Street, just five Labour MPs ultimately supported May.

  1. Parliamentarians tried to legislate against prorogation – but they made a crucial error

In mid-2019, with May overthrown and the Conservative leadership contest to replace her underway, some politicians began to fear that Parliament might be prorogued to prevent it from hindering a no-deal Brexit. The possibility had been mooted by leadership contender Dominic Raab, and while most candidates had vocally disavowed the suggestion, front-runner Boris Johnson had remained cagey.

The prorogation power is exercised by the monarch on the Prime Minister’s advice, with no Commons vote required, so opponents needed to show procedural ingenuity. The government’s Northern Ireland (Executive Formation) Bill – required to keep the region’s institutions running without an executive – provided an opportunity. Rebels inserted amendments requiring Parliament to sit every two weeks to hear a report on progress in restoring power-sharing, effectively preventing a lengthy prorogation.

But the rebels made a crucial tactical error. A five-week gap was left in the reporting schedule, over the usual party conference period. Some Conservative interviewees claimed (perhaps unsurprisingly) that the loophole was included at Jeremy Corbyn’s insistence, though its origins are ultimately unclear. But it allowed Johnson to pursue a five-week prorogation – later ruled unlawful by the Supreme Court.

  1. Johnson planned to renege on his ‘oven-ready’ Protocol

In autumn 2019, Johnson proclaimed his renegotiated deal with the EU a triumph. In essence, he had traded May’s all-UK customs union for a border down the Irish Sea: choosing divergence between Great Britain and the EU over alignment between Great Britain and Northern Ireland.

Johnson’s team knew that this stored up problems for later. But their short-term priority was to persuade MPs to pass the deal – even if that meant suppressing the reality of the trade-offs.

Two groups were key. The DUP was implacably opposed to any border down the Irish Sea; to add insult to injury, Johnson had publicly told them he would contemplate no such thing. The other key group was the ERG – also concerned about the deal, but increasingly worried about the risk of losing Brexit altogether.

Members of both groups have independently reported that Johnson promised he would later renege on the deal in return for their support – apparently a promise key to securing the ERG’s votes. This is the deal that Johnson went on to sell to the electorate as ‘oven-ready’ in the 2019 general election campaign. Rishi Sunak has recently sought to resolve its problems via the Windsor framework, but it still lacks DUP support.

By Professor Meg Russell, Director, Constitution Unit, UCL, and former Senior Fellow, UK in a Changing Europe, and Lisa James, Research Fellow, Constitution Unit, UCL.  

The Parliamentary Battle over Brexit was published by Oxford University Press on 23 March. Click the link for further details about the book, and to purchase it with a 30% discount on the £25 retail price.


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