Labour would be unlikely to hold an in/out referendum on membership of the European Union if Ed Miliband becomes prime minister, the Labour leader admitted today.
Setting an "arbitrary timetable" for a referendum would "inflict huge uncertainty on business and undermine Britain's influence abroad" Miliband insisted in an article for the Financial Times.
He said that Labour would call an in/out referendum if there were any significant new transfer of powers to the EU, but added it was "unlikely there will be any such proposals in the next parliament".
Miliband's commitment drew immediate plaudits from pro-European figures in the Labour party.
Peter Mandelson, who has long been critical of the Labour leader, said Miliband had shown "judgement and courage."
"I think it will be seen over time as quite a game-changer for Ed Miliband," the former business secretary and EU commissioner told the Today programme.
"I think he's shown judgment and courage. I think he's gone out and made the political weather on a major issue and I think as a result it will strengthen him and help him win the next election."
Others in the party were more critical.
Labour MP John Mann told the World Tonight that Miliband risked appearing out of touch with voters.
"Certainly I've polled very extensively Labour voters in my area, and without question, they're more hostile than they were to the European Union - significantly more so - and I think that we need to be in touch and we need to be trusting the people."
Miliband also set out his plans to reform Britain’s relationship with Europe.
In a speech in central London, the Labour leader said that Labour would make it harder for EU migrants to claim child benefit and tax credits as well as make it easier for the UK to deport migrants who have committed a crime.
He also sought to lengthen the transitional arrangement for immigrants arriving from new member countries to ensure that they have to wait longer before gaining rights to work in the UK.
Miliband's announcements were broadly welcomed by business leaders this morning.
"Business will welcome Labour’s decision to make its policy position on Europe clear," CBI President, Mike Rake said.
"Any uncertainty is unhelpful when trying to secure long-term investment.
"The CBI strongly supports Ed Miliband’s view that we are better off in a reformed EU than outside with no influence. We must take a sensible approach to building alliances to get the reforms we need.
"Calling a referendum is a matter for politicians to decide. But business believes that future investment, growth and jobs depend on the UK being part of a competitive and outward-looking EU."
Miliband’s pledge comes as a new poll shows support for staying in the EU is growing.
The YouGov poll for the Sun found that more people now want to stay in the EU than leave it, with 41% saying they want to remain as opposed to 39% wanting to leave.
Miliband is thought to have been convinced by other polling that shows that while the public are broadly split over the issue, it is still only a minority concern for voters.
Polling by Ipsos Mori, found that concern over Europe remains at historic lows with less than one-in-ten voters listing it as an important issue facing Britain.
The Conservatives are now expected to make their commitment to an EU referendum a defining issue of the next election.
David Cameron insisted today that only the Tories would "guarantee" a vote on Europe.
"By his own admission, Ed Miliband says it's unlikely there'll be an in/out referendum on Europe under Labour," the prime minister posted on Twitter.