David Cameron is expected to confirm on Tuesday that he will allow ministers to campaign for exit from the EU once his re-negotiation is complete.
His decision is likely to avoid the resignations of several senior ministers over the referendum, such as Iain Duncan Smith, the work and pensions secretary, who is a staunch Eurosceptic. Others likely to campaign for the UK to leave include Chris Grayling, the leader of the house, and Theresa Villiers, the Northern Ireland secretary.
A source said the prime minister was planning to set out his thinking when he makes a statement on the December European summit to the House of Commons on Tuesday afternoon.
Cameron is hoping to complete negotiations with Brussels at the February summit, at which he wants to win concessions on national sovereignty and migrant benefits.
But some strongly Eurosceptic ministers are unlikely to believe that is enough to persuade them to want to stay in the EU when Cameron calls his referendum on Britain’s membership by the end of 2017.
Cameron may not make the announcement in the EU statement itself but it is likely to come up in questions.
A Downing Street source said the prime minister was clear that collective responsibility will hold until the negotiations are complete.
The development will prompt speculation that the EU referendum will be called as soon as possible after Cameron has concluded his deal in Brussels.
Matthew Elliott, the chief executive of the Vote Leave campaign, said it could be as near as 170 days away. He said: “We welcome the prime minister’s decision to allow ministers to campaign openly in the referendum. We hope that many ministers will speak out honestly about how much of their jobs are now really controlled by Brussels, not by the votes of the British public, and how it is much safer to Vote Leave.
“The referendum could be as little as 170 days away, so ministers should be allowed to campaign openly as soon as the renegotiation is complete – and certainly no later than the end of the European council in February. The British people deserve to hear where their elected representatives stand on this vitally important issue.”
At the end of last year, Steve Baker, the co-chair of the Conservatives for Britain campaign to leave the EU, said most Tory MPs were leaning towards voting for the UK to leave as the mood of the party had hardened against Cameron’s attempted renegotiation.
Baker, whose group is allied to the cross-party Vote Leave campaign, said: “Over half of the Conservative party is strongly leaning to leave.” In light of the clear split, he warned there would be “problems ahead” if the prime minister did not allow free campaigning on both sides of the debate.
“I think for the sake of the country, party and quality of debate it would be much better if ministers have freedom to speak their mind on the EU issue,” he said at the time.
His warning was echoed by other senior Tories including Liam Fox, the former defence secretary, and Graham Brady, the chairman of the backbench 1922 Committee, who said it would be a “catastrophic mistake” for Cameron to force all ministers to campaign for staying in the EU.
No cabinet minister has been able to publicly declare they back Britain leaving the EU because of collective responsibility, but Eurosceptic sources believe Theresa Villiers, Chris Grayling and Iain Duncan Smith would be likely to resign rather than campaign to remain. Other cabinet ministers and senior figures who could go either way include John Whittingdale, Sajid Javid, Michael Gove, Boris Johnson and Theresa May.
Cameron claimed he made progress with European leaders in a discussion about his renegotiation demands at a Brussels summit in mid-December.
The prime minister wants concessions from Brussels on his demands for greater veto powers for national parliaments, protections for non-eurozone countries, an end to “ever closer union” and curbs for migrant benefits – but the last of these has met with significant opposition from other EU leaders.
The polls suggest the vote could be close, with public opinion showing as increasingly Eurosceptic. An ICM poll for the Vote Leave campaign found 50% of voters were in favour of leaving, if those who said they were undecided were excluded. Overall, 41% wanted to leave while 42% wanted to stay, and the rest did not know.
The poll, published in the Daily Telegraph, found the numbers were different if Cameron failed to win any concessions on freedom of movement and curbing migration. In that case, 45% would vote for a Brexit and 40% would back staying in the EU – or 53% to leave and 47% to remain, excluding undecideds.
This article was written by Rowena Mason Political correspondent, for theguardian.com on Tuesday 5th January 2016 11.41 Europe/Londonguardian.co.uk © Guardian News and Media Limited 2010