David Cameron is a "coward" for wanting to hold a referendum on Britain's membership of the European Union, a Lib Dem peer and close ally of Vince Cable has said.
On Friday the House of Lords debated the Conservative Party's EU Referendum Bill, which would commit the next government to holding an in/out referendum by 2017. The pledge is a key plank of Cameron's 2015 election pitch, designed in part to stop the Tories hemorrhaging votes to Ukip.
Lord Oakeshott told peers the Bill was "utterly unnecessary" and warned a referendum would do "serious damage" to the British economy as well as "stability and security" in Europe.
"It's playing with fire for long term confidence and investment from all over the world," he said. "The more referenda I see, the less I like them."
"Referenda are the coward's way out. They are an abdication of responsibility by leaders and parties who haven't the courage to take a decisions and put it to the people.
"There's no need for a referendum on Europe when there is a clear choice at the general election. If you want to come out of Europe you vote for Ukip. If you want to stay in you vote Lib Dem or Labour. If you don't know or don't care, you vote Conservative."
The Lib Dem peer also said the fact Britons living in Europe would not be given a vote in the referendum as the Bill was currently written was "a betrayal of their trust".
Conservative MP Rob Wilson hit out at the Lord Oakeshott, who is probably Conservative's least favourite Lib Dem. "I am always suspicious of politicians who know better than the people that elect them - although I guess Lord Oakeshott doesn't need to concern himself with elections and the will of the people," he told HuffPost UK.
Tory peer Lord Dobbs, who is piloting the Bill through the Lords on behalf of the prime minister, told peers "the people have the right to decide their own future".
"A referendum is about democracy," he said. "It's not about being anti-European or pro-European, it's about people being able to decide their own future. It will be a brave man who denies them that choice."
The Labour Party, along with the Lib Dems, are opposed to the Bill. And Conservatives expect them to try and scupper the chances of it becoming law by tabling a large number of amendments to ensure there is not enough time for it to complete its passage through parliament.
Lord Strathclyde, the former Tory leader of the Lords, said as peers were unelected they had the "power to block this bill, but not the authority".
Lord Mandelson, the former Labour business secretary and EU commissioner said Cameron was "grandstanding to the Ukip gallery" with the promise of a referendum and had been "taken hostage by the militant tendency" within his own party.
"If you are really serious about European reform you have to go out and work for it and join with others in achieving it," he said.
The Lords need to finish scrutinising the Bill before 28 February or it is unlikely to become law. If Labour and the Lib Dems succeed it will be a blow to Cameron ahead of the European elections in May, which Ukip are hoping to win.