Government ministers are to be free to campaign o n either side of the referendum on Britain's continued membership of the EU, Prime Minister David Cameron has confirmed.
Mr Cameron told the House of Commons that the Government will make a "clear recommendation" on whether the UK should stay in the 28-nation bloc or leave, following the conclusion of the renegotiation of the terms of its membership.
But he told MPs that it would be open for individual ministers to oppose this recommendation without quitting their Government posts, in a significant departure from the usual principle of collective responsibility.
The move will throw a spotlight on senior Tories such as Home Secretary Theresa May, Work and Pensions Secretary Iain Duncan Smith, Leader of the Commons Chris Grayling and London Mayor Boris Johnson, who will face increased pressure to declare which way they will vote.
In a statement to the Commons on last month's European Council summit, Mr Cameron said: "My intention is that at the conclusion of the renegotiation, the Government should reach a clear recommendation and then the referendum will be held.
"But it is in the nature of a referendum that it is the people, not the politicians, who decide.
"As I indicated before Christmas, there will be a clear Government position, but it will be open to individual ministers to take a different personal position while remaining part of the Government.
"Ultimately, it will be for the British people to decide this country's future by voting In or Out of a reformed European Union in the referendum that only we promised and that only a Conservative-majority Government was able to deliver."
Mr Cameron said that last month's summit set out a "pathway" for agreement among EU national leaders meeting in Brussels in February on a package of reforms to satisfy UK concerns. He has previously indicated that this could set the scene for a referendum later this year, with many observers speculating on a date in June or July.
The Prime Minister has made clear that he will campaign for continued UK membership if his renegotiation is successful. But he repeated his insistence that, if a satisfactory package cannot be agreed, he "rules nothing out".
Mr Cameron had come under mounting pressure to suspend collective Cabinet responsibility, with several senior eurosceptic figures thought to be ready to quit if they were forced to back an "in" vote.
His party remains deeply divided, with MP Steve Baker, of the Conservatives For Britain group, recently suggesting more than half of his colleagues were "strongly leaning to leave".
But former prime minister Sir John Major had previously urged the PM to maintain collective responsibility throughout the campaign, while ex-deputy prime minister Lord Heseltine warned a free vote would make Mr Cameron a "laughing stock".
Former chancellor Kenneth Clarke said frontbenchers should resign if they disagree with the Government, and "firm ground rules" were needed to ensure Cabinet ministers campaign "moderately" and "don't get carried away".
Mr Clarke, a staunch pro-European, told BBC Radio 4's World At One that the PM faced a "very difficult task" if he was to "avoid splitting the party" and claimed he had been "forced into" his announcement by ministers briefing the media that they could quit.
Alan Johnson, the chair of Labour In for Britain campaign, told the BBC: "It's a strange way to run a country. The Conservatives have a number of extremists in their party on Europe - they always have had - and I think this is the latest manifestation of that.
"The Prime Minister will go and negotiate an agreement and come back and put in to the Cabinet - where in my 11 years in cabinet collective responsibility held - and whoever wins in that debate, that will be Government policy. And yet Government ministers will be able to go off and argue in a different way.
"This is not an issue like abortion or euthanasia which is traditionally a free vote. This is very fundamental to running the country."
Mr Johnson, who insisted Labour was "united on the issue of Europe", added: "Whatever view you take on (leaving) Europe, it's a very dangerous and precarious step to take and not to have a Government united behind the Prime Minister on that seems to me strange."
Liberal Democrat leader Tim Farron said: "The Prime Minister is failing to lead his own Government, let alone the country, putting his own internal party strife above what's best for Britain.
"Now is not the time to back down. The Government should take a collective position on this issue, and if ministers disagree with the Prime Minister they should resign."
But Brian Monteith of the Leave.EU campaign, said: "We welcome the news that ministers will be allowed to campaign with their conscience in the referendum.
"However, this is not about them. It will be ordinary people such as nurses, taxi drivers and small business owners that need to have their voices heard in this debate."