Chancellor George Osborne has said it would be "odd" for Labour and the Liberal Democrats to go into the next general election telling voters that they do not trust them to make a decision on Britain's future in Europe, while the Conservatives do.
Mr Osborne piled additional pressure on both Labour and the Lib Dems, who have refused to match Prime Minister David Cameron's promise of an in/out referendum on EU membership in the course of the next Parliament.
And the Chancellor rejected the warning from Lib Dem Deputy Prime Minister Nick Clegg that the referendum pledge will create damaging uncertainty for business by "tying us up in knots" for years.
Mr Osborne told BBC1's Breakfast: "I don't agree with him on this and I don't think it's any secret that Liberal Democrats and the Labour Party don't think the people should be asked about our future in Europe, whereas the Conservative Party does."
Many businesses have said that one of Britain's biggest problems is the burden of tax and regulation from Europe, he said.
And he added: "I think the business community understands what we are doing. Above all, people can be trusted with their future and their country's future. I think we could find ourselves in a very odd situation if we get to a general election and parties like the Labour Party and the Liberal Democrats are not prepared to trust the people.
"The Conservative Party is prepared to trust the people and we are going to ask people's consent for that at the next general election."
London Mayor Boris Johnson has launched a broadside at Labour leader Ed Miliband for failing to offer a referendum on EU membership.
And Mr Johnson made clear he was ready to contemplate UK departure in the event of a No vote, saying exit might not be "the catastrophe some people claim". Mr Miliband told the House of Commons last week that he did not want an in/out referendum, though aides later said he was not ruling it out forever, but did not believe it was right to promise one now.
Writing in the Daily Telegraph, the Mayor said: "He has painted himself into a corner. He has entered a lobster pot, and he is going to find it hard to back out with any kind of dignity - though I have no doubt that he will soon begin to try..."