Labour has attempted to ratchet up the pressure on Chancellor George Osborne by calling for a two-year stamp duty holiday for first-time buyers.
Shadow chancellor Ed Balls said suspending the levy on properties worth less than £250,000 would help revive the housing market and wider economy.
However, in an eve-of-conference interview with the Sunday Telegraph, he also made clear that he could not yet promise to reverse any specific coalition spending cuts.
The comments came with Mr Osborne facing demands from the Tory right to cut taxes in his December financial package.
"With every month which goes past the position is getting worse," Mr Balls said. "We will have a very difficult inheritance... And that's why I've been absolutely clear with my Shadow Cabinet colleagues - and all of them accept (this) - that we can't make spending commitments now.
He insisted that Mr Osborne had only himself to blame for criticism, after he announced the top rate of tax was being cut from 50p to 45p.
"To be honest, any tax cut at the moment which helps families, boosts spending power, gets jobs being created and gets our deficit down is better than nothing," he said. "But not the top rate of tax. I think the top rate of tax cut is probably one tax cut which doesn't have that effect, because it only goes to the richest.
"What George Osborne has managed to do is an astonishing political achievement. He's actually managed to unite (former defence secretary) Liam Fox, (London Mayor) Boris Johnson, me and Harriet Harman, all agreeing that we need tax cuts now."
Mr Balls said he would spell out how he wants to fund the stamp duty holiday in his speech to conference.
The last Labour government took the same action in 2010, but the scheme has now run out. "Bring it back," demanded Mr Balls. "We can actually do something to help aspirational men and women who want to get on the housing ladder and are finding it really hard at the moment."