'Stability budget Lib Dem red line'
An emergency "stability budget" within the first 50 days of the next parliament will be a Liberal Democrat red line in any post-election deal.
Nick Clegg's demand would effectively veto the Tory plan to cut £12 billion from the welfare budget to balance the books if the Lib Dems teamed up with the Conservatives again.
If the Lib Dems were in coalition with Labour, the demand would impose a timetable on Ed Miliband and Ed Balls to deal with the deficit.
The move follows Mr Clegg's decision to start explicitly setting out the terms the Lib Dems would demand in any deal after May 7.
He has already declared that a commitment to increase the education budget to keep pace with rising prices and the growth in pupil numbers will be a "no ifs, no buts" red line.
At a press conference in central London, Mr Clegg set out his latest conditions to Mr Miliband and Prime Minister David Cameron.
Positioning his party as being able to offer stability, Mr Clegg said: "Whether we are in government with Labour or the Conservatives, we will pin them down within weeks of the election and force them to put their cards on the table.
"David Cameron, Ed Miliband - the Liberal Democrats won't let you bluff your way through. We won't let you risk our economic recovery.
"We will have a stability budget, to take place within 50 days of election day, a pre-condition of any coalition arrangement.
"There will be no deal if there is no stability. No coalition without coming clean with the British people. This too, is a red line.
"But it is also a means to an end. It is a guarantee to the British public that the Government will balance the books, following a clear timetable, and do so fairly.
"Let me tell you what will lie at the heart of it - a commitment to balance the books, in a timely fashion and in a fair way, and a clear commitment to our world-class public services, including the money that our nurseries, schools and colleges need."
The Lib Dem leader has previously condemned Tory plans to balance the budget by cutting £12 billion from welfare without increasing taxes on the wealthy. He has also criticised Labour for failing to set out a clear timetable for eliminating the deficit.
Mr Clegg acknowledged that not every detail could be finalised now, but his plan would "calm jittery markets, keep interest rates low, keep Britain on track, and show the British people how we will finish the job fairly and continue to support our public services".
He added: "We won't let Labour risk your job or our economy with reckless borrowing. And we won't let the Conservatives risk our schools, hospitals and public services with reckless cuts.
"There is little over a week until the British people have their say. So it is time for Labour and the Conservatives to come clean. But if they won't, the Liberal Democrats will keep them on the straight and narrow."
The stability budget will set out detailed tax and welfare plans to balance the cyclically adjusted current budget. Remaining savings from departmental expenditure will be detailed in a Comprehensive Spending Review to be held in autumn 2015.