Some legislators claim the measure doesn't have enough support to pass.
Democratic leaders are trying to get the tax hike passed before a new legislature is sworn in next week.
The lawmakers are scheduled to return to Springfield on Sunday to continue work on the tax hike.
Under the proposal, the state income tax will rise from 3 percent to 5.25 percent for the next four years. It would then drop to 3.75 percent.
That means someone who currently pays $1,000 in state income tax would pay $1,750 a year. After four years, their state tax bill would drop to $1,250.
Without a fully-formed tax increase bill to consider, and apparently some cracks in party unity, Springfield's Democratic boss sent lawmakers home Friday morning with orders to return to Capitol two day from now.
House members were not entirely surprised when Speaker Michael Madigan suddenly adjourned the session until Sunday.
"There are people working behind the scenes at the governor's office and the president's office, working to get the bill ready and the language drafted so we're ready to go on Sunday," said Rep. Will Burns, (D) Hyde Park.
Wednesday night Madigan, Senate President John Cullerton and Gov. Pat Quinn agreed on a plan to use Democratic majorities in the House and Senate to approve a 75-percent increase in the state income tax.
The controlling party has abandoned efforts to get support from republicans who expressed new outrage at the size of the proposed increase.
"People here are speechless. I think the Democrat plan is to get everybody out of town. They want as little attention as they can get," said Rep. Tom Cross, House minority leader.
Opponents say the Democrats' decision to wait until sunday could help the anti-tax increase effort.
"I think by leaving it open for the weekend, people will get more constituents to call and tell them please don't do this," said Rep. Elizabeth Coulson, (R) Glenview.
Not all Democrats are on board, despite what the powerful Madigan might want.
"They know my position on the tax increase. I am not for it. I'm a moderate Democrat," said Rep. Carol Sente, (D) Vernon Hills.
Des Plaines Rep. Elaine Nekritz (D) says the tax bill should include a state government spending cap.
"If we exceed that, that the income tax increase would automatically be revoked," said Nekritz.
But most Democrats say the deficit requires a yes vote for a tax increase.
"The question become not if but how much and where it is directed to. And are we going to do what we think is right and responsible, or are we going to use this for political purposes," said Rep. David Miller, (D) South Suburbs.
With the state Senate having to approve whatever the House decides, there can be no resolution before Monday when Gov. Pat Quinn is scheduled to be inaugurated. It's an event surely to be overshadowed by the state's fiscal and political crisis.