The Liberal Democrats would not back a governing party which proposes "merrily slashing" public spending immediately, Nick Clegg has said.
Speaking as his party's spring conference got underway, Mr Clegg said that the Lib Dems opposed starting to address the public spending deficit in the 2010/11 financial year.
His comments are in sharp contrast with those given in a Guardian interview on the eve of the party's autumn conference last year, when he said "savage cuts" were needed.
"There's no point pulling the carpet out from under the feet of the British economy when it's still struggling standing up," he told the Today programme this morning.
The Lib Dems remain reticent about which party they would back in the event of a hung parliament, but Mr Clegg's comments today suggest on economic issues the party might be more closely aligned with Labour than the Conservatives.
"We think merrily slashing now is an act of economic masochism," he added.
"If anyone had to rely on our support, we would say 'no, do it sensibly... explain to the British people and to the financial markets that we have a better plan than anyone else to fill the black hole that Gordon Brown's created in the finances, but do it at a time that's economically sustainable'."
Conference delegates backed plans to increase the threshold at which people start paying income tax from current levels to £10,000.
"The Liberal Democrat plans are the most radical, far reaching tax reforms in a generation and embody everything that we stand for: fairness, protecting the environment, rewarding hard work," Treasury spokesman Vince Cable said.
Under the proposed changes the average person's income tax bill would be cut by £700, with 3.6 million people not paying any income tax at all.