The issue of EU membership has haunted both the Conservative and Labour parties almost from the first suggestion of the UK joining in the immediate post-war period.
While tensions within Labour ebbed and followed over the following decades, the 2016 referendum really opened Pandora’s box, and the party has been dealing with the consequences ever since (along with the country and every other political party in it).
Each party has faced different challenges over Brexit.
The Conservatives have been more entrenched in their pro-Brexit views, shedding leading members along the way.
We might have expected to see the Labour Party, desperate for power, to occupy the Remain side of the argument – while the Tories could fight with the Brexit party over their occupancy of the right, Labour would be able to fight off the Liberal Democrats by offering a referendum promise.
However, while this might have seemed a logical course of action, it was not without its issues.
Firstly, and perhaps most importantly, the Labour Party are not in government, so any promise they made would have to follow a general election victory.
This might have some advantages for the party in opposition, allowing them to maintain their attack on the Conservatives without having to get involved in the nitty-gritty of actually trying to negotiate a withdrawal agreement themselves.
However, as with all seemingly simple ideas, there were some huge issues to overcome. Immediately after the 2016 referendum, it became accepted wisdom that the north of England, the bedrock of Labour, had voted overwhelmingly to Leave.
How could the party contemplate sacrificing dozens of seats with no guarantee that a Remain stance would gain them any new ones?
This suspicion was coupled with the long established views of their leader.
Jeremy Corbyn is a committed eurosceptic, having spoken in public on numerous occasions during his political career on the potential benefits of leaving the EU. As even his detractors will admit, a volte-face from Corbyn is unlikely, and that puts the wider party into a difficult position.
Corbyn and his supporters, a very strong and influential voice within the party, would find a strong Remain policy deeply uncomfortable, and the potential losses in the north allow them a strategic reason for keeping faith with their existing views.
But what of the Labour Remainers? While the Parliamentary Labour Party is undoubtedly dominated by Remainers, there is also a strong Remain strand amongst Labour voters.
As voting data collected in the wake of the referendum showed, even in the strongest of Leave constituencies, the Leave vote was not made up entirely of Labour voters, meaning that individual voters within Labour constituencies might vote Labour, but also Remain.
This point appears to have been largely lost on those encouraging Labour’s Leave credentials, but you can see the quandary. When an issue does not separate neatly along party lines, it is essential to try to pick a policy which will appeal to the maximum number of people.
Often those sorts of solutions are convoluted and please no-one.
After the referendum, Labour’s immediate response was to call for the triggering of Article 50, to enact the result as quickly as possible.
Over the weeks and months which followed, as the true extent of Britain’s integration with the EU and the necessary sacrifices which were needed for Brexit to be enacted became clear, the party began to change its policies.
As the Yellowhammer documents eventually emphasised, any negative effects of Brexit would undoubtedly hit those close to the poverty line first. How could the party of the working class campaign and argue for such an outcome?
To pick either policy would require an iron grip on the party and an iron will to drive it through, regardless of the impact on the party. Without these, a messy compromise was required, and that was what was created.
One way out of this predicament was to follow the well-worn path of Wilson and Cameron – the referendum.
After Harold Wilson’s failed attempt to persuade the EEC members to allow Britain’s entry in 1967, he was understandably concerned that Heath’s success in 1973 would be electorally disastrous for the party.
How to maintain unity in his own party, while criticising Heath and gaining an electoral advantage?
Wilson’s solution was to propose renegotiating Britain’s terms of entry and then holding a referendum. This would shield his party from the negative effects of a public war over the issue.
Corbyn and his supporters appear to have taken a leaf out of the Wilson playbook: build the push for a second referendum into a manifesto pledge, and hope that that wins them the election.
But what to put on the ballot? There would have to be a Remain option, but what else?
May’s Withdrawal Agreement was so unpopular that this would never be an option; plus it would simply be a way for the Conservative Party to take credit for a practical proposal and give their supporters something to coalesce around.
Far better to create a withdrawal agreement of your own and put that on the ballot paper too, while still accepting it wasn’t as good a deal for Britain as the existing terms of membership.
That being the case, the party could argue it had done its best, created a decent withdrawal agreement but campaign to Remain
While the May government clung onto a majority through its deal with the DUP, that position, while confusing, could be just about maintained. The inevitable problem would come when the party was forced to actually attempt to sell this to the public when the May government fell.
When Johnson became Prime Minister, strategic missteps in early September soon destroyed his slim majority.
This meant that Labour’s policy, which had been up to this point, largely abstract, needed to become more realistic – and quickly. Many within the party had been working to formulate a detailed policy, but sequencing the referendum and general election continue to cause problems.
Jeremy Corbyn and his supporters (most notably Len McClusky) prefer a general election before a referendum, while his deputy Tom Watson wants a referendum followed by a general election.
The timing and sequencing of those events may not be in the gift of the Labour Party as they may well be overtaken by events if Johnson resigns, but the internal battle feeds the acrimony at the centre of the party.
The question of sequencing really highlights the key issue for the party – what matters most, stopping Brexit or getting into government?
For those voters who might be tempted to lend Labour their support, they may need reassuring that the party isn’t using Brexit to its own advantage and that a general election win wouldn’t lead to a change of policy, or even to the party dragging their feet on a second referendum.
The party still has a long way to go before it has a clear Brexit policy which will bring Remainers on board in the numbers needed to get them into Downing Street. Their internal fighting isn’t helping their cause.
By Dr Victoria Honeyman, Lecturer in British Politics at the University of Leeds.