The politics behind Cameron's referendum U-turn

Conservative MPs are particularly delighted with their leader’s plans to renegotiate the UK often unhappy membership of the EU, before giving them the referendum which many of them have craved for a generation.

All of which may have been responsible for the UK prime minister throwing caution to the wind at the weekend, when he dropped the strongest possible suggestion that ministers wishing to defy him and campaign for a Brexit at the anxiously awaited referendum in 2016 or 2017 would have to resign from his government.

“I’ve been very clear. If you want to be part of the government, you have to take the view that we are engaged in an exercise of renegotiation, to have a referendum and that will lead to a successful outcome,” he said at the G7 summit in Bavaria on Sunday evening.

Clear enough, right?

So clear - not to say provocative - that within hours of headlines proclaiming ‘back me or resign’, Cameron’s media machine had backtracked.

"It's clear to me what I said yesterday was misinterpreted," Cameron told reporters on Monday, explaining that he was only talking about the renegotiation process, adding that he “rules nothing out” if fellow EU leaders do not give him satisfaction on proposed reforms.

The bizarre U-turn at the G7 summit is a reminder of the Conservative party’s deep sensitivity on the question of EU membership.

Cameron is under fierce pressure from his party to remove ministers from the shackles of having to abide by the principle of ‘collective responsibility’ for the period of the referendum campaign. On Tuesday (9 June), London mayor and Conservative leadership hopeful when Cameron stands down ahead of the 2020 election, Boris Johnson, also called for a free vote on the grounds that it would be "safer and more harmonious".

In the House of Commons on Tuesday, MPs held their first debate on the EU referendum bill. With the opposition Labour party backing the bill, and only the 56 SNP deputies standing in its way, it will find its way onto the statute book relatively easily.

What happens then is anyone’s guess. Labour and the SNP will back a ‘Yes’ vote, while the number of Conservatives campaigning for a ‘Yes’ will depend entirely on how much Cameron is able to claw back from EU leaders.

"The prime minister is probably for in, but he can't say definitely he's in or out because a lot of his MPs are for out unless they can be persuaded to be in," said Labour foreign affairs spokesman, Hilary Benn during Tuesday’s debate.

In Cameron’s cabinet, pensions secretary Iain Duncan-Smith, who rebelled against the Maastricht treaty back in the early 1990s, is the most obvious candidate to campaign for a ‘No’ vote. Business secretary Sajid Javid and Justice secretary Michael Gove are also likely to join him unless Cameron is spectacularly successful in the negotiations.

Conservatives insist that there will be no blood letting when the poll finally takes place in 2016 or 2017, but it is hard to take this at face value. What is more likely is that roughly a quarter of the 331 Conservative MPs will campaign for a ‘No’ vote regardless of what Cameron is able to secure from fellow EU leaders. The launch of the Conservatives for Britain campaign group at the weekend, to which more than 60 MPs have already signed up, is likely to be the focal point for the Conservative ‘No’ campaign.

Labour prime minister Harold Wilson gave his ministers a free run at the referendum on the then EEC in 1975, temporarily freeing them from the principle of ‘collective responsibility’. Left-wing eurosceptics Tony Benn and Barbara Castle subsequently became leading figures in the ’No’ campaign, before returning to the same cabinet table as prominent Yes’ campaigners like Roy Jenkins.

In the 1970s it was Labour that was deeply divided on the question of EU membership. More than 40 Labour MPs broke the party whip to support Edward Heath’s bill which confirmed the UK’s membership of the EEC, and divisions on Europe were one of the key factor in the creation of the breakaway Social Democrat Party, founded by four former Labour cabinet ministers, which came close to destroying Labour as a political force in the early 1980s.

Governments tend to only allow ‘free votes’ on matters of conscience, although Europe has long been an article of faith for a section of Conservative party. As Labour and Wilson demonstrated in the 70s, having to hold a ‘free vote’ would be the mark of a divided party.

Yet despite last month’s election triumph, and the protestations that they will not repeat the self-destructive infighting of the Nineties and Noughties, that is what the Conservatives remain when it comes to the EU.