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 slice of the Queen and Prince Philip's wedding cake has sold for £500 at auction, 68 years after the couple got married.
A man has 'potentially life-changing injuries' after acid was thrown over him after a screening of the movie Straight Outta Compton.
A leading sexual health clinic has apologised after mistakenly sharing the HIV positive status of hundreds of patients in an email.