Ed Miliband should hold his nerve and not be "dragged along by the Ukip bandwagon" on Britain's membership of the European Union, former Labour minister and ex-European Commissioner Lord Mandelson told ITV News.
The Labour leader previously said he was against holding an in-out referendum under the terms proposed by Prime Minister David Cameron.
Lord Mandelson told Libby Wiener: "I think Ed Miliband is right to stand his ground but also to say that if there is in the future a need for, circumstances arising that require a referendum, then of course a Labour government would agree to that and put it to the British people".
More top news
A hacker group who claimed to be behind a cyber attack on Sony Pictures have posted a message online apparently mocking the FBI.
The returns of Benedict Cumberbatch's detective and the X Factor judge were among 2014's most tweeted TV moments in a billion conversations.
A family has issued an appeal to help find their missing pet turkey - in case he gets gobbled up as someone's Christmas dinner.