Liberal Leader Michael Ignatieff demanded more accountability before signing off on the government's plans to stimulate the economy Tuesday, accusing Prime Minister Stephen Harper of playing politics and making threats while the Canadian economy deteriorates further.

"We want accountability before we vote, and we want accountability after we vote," Ignatieff told reporters in Ottawa.

"We cannot write a blank cheque on $3 billion worth of stimulus. We have to have some indication of what this is going to be spent on."

On Tuesday, members of Parliament were scheduled to vote on the "report stage" of the budget, one of several sessions before the House votes for a final time and the budget moves on to the senate.

Ignatieff said more detail on specific spending plans for the $3 billion emergency stimulus fund is a reasonable demand during the process.

"If we can get $3 billion out fast, I'm happy to do it, but I'm not writing blank cheques and he has to understand that," he said.

But as he was asking for more accountability from the Conservative government on spending plans, he also put pressure on the Senate to quickly sign off on the money and "get [it] out the door."

"This economy is sinking like a stone and my party wants to be constructive and positive," Ignatieff said.

"We are in a hole. Responsible politicians start digging us out of the hole and that's what I hope that the Senate will do.

"We feel very strongly that we're in a national crisis. We have not seen economic results like this in a generation," Ignatieff said.

"I'll pass [on] that message in no uncertain terms."