The strains and stresses on the proposed $27.9 billion state budget package reached a breaking point Thursday.

After two days of closed-door talks, House Democrats altered the tax package that was part of an agreement that legislative leaders reached last month.

The immediate impact was to throw a cloud of uncertainty over the process that appeared to be lurching toward a conclusion as recently as a week ago.

House Democratic leaders said it became apparent that the changes were needed if the deal was to stand a chance of passing the full House today.

The Democrats hold a 104-99 majority in the chamber, but the House Republicans are not a party to the budget deal.

Democratic caucus leaders said they felt their actions Thursday kept faith with the negotiated agreement, noting that their changes would not raise spending and still would avoid a broad-based tax increase such as in the state income tax.

"We listened to our members," Majority Leader Todd Eachus, D-Luzerne County, said.

The tax-package changes that the Democrats pushed through the House Rules Committee on a party-line vote included:

Dropping the proposed ticket tax on live stage events and cultural attractions such as zoos and museums, a proposal that has been widely unpopular with arts advocates.

Dropping the tax on proceeds from small games of chance run by organizations that hold liquor licenses.

Including a 30 percent tax on the wholesale price of cigars and smokeless tobacco products.

Adding a severance tax on natural-gas drilling.

Setting the upfront licensing fee for table games at casinos at $20 million and the tax rate on casino winnings from table games at 34 percent, which is equal to the tax rates on slot machines.

Other components of the tax package were left intact, including a tax amnesty plan, a cigarette tax increase and a hike in the state's tax on business assets.

The revisions left Senate Republicans feeling betrayed.

"If they would have come to us and said they couldn't deliver on the votes on what they agreed to, we'd have had a discussion and tried to work things through," said Jake Corman, R-Centre County, chairman of the Senate Appropriations Committee.

"But to go ahead and move something completely different just for the sake of doing it is not honoring your word. And it makes it difficult to come up with a future deal, because what are we going to handshake on next that they are going to turn on?" Corman said.

He said the House will set the budget process back a few weeks if it passes its revised tax package today.

If the House passes the proposed changes but the Senate rejects them, the tax dispute could be forced into a House-Senate conference committee for negotiation. But some House Democratic leaders said the issues that the conference committee would have to discuss would be limited.

The Senate also could try to launch a new round of override votes on Gov. Ed Rendell's vetoes of line items in the partial budget that was passed in August.

The state has been without a final budget since July 1. That has forced human-service organizations to shut down, cut services or lay off staff. Tony Ross, president of United Way of Pennsylvania, has warned of a major catastrophe if these agencies do not receive state funding by mid-October.

School districts and counties have been pushed to borrow to keep their operations running.

House Democrats' opposition to the small-games tax and the arts ticket tax was evident even before they reviewed the plan's details this week. They also were disappointed with the proposal to lease more state forest land for natural-gas drilling while not taxing that production.

Eachus said the revised package "affirms much of what we agreed on with our partners [in the Senate]. It takes out some issues we thought were problematic."

"We do not want to tax fire companies, VFWs and civic organizations who pour a lot of money into youth programs, blood banks and other things," said Rep. Robert Belfanti, D-Northumberland County. "We stood firm against big tobacco ... big casinos and ... big insurance in this caucus. For the Senate to send us a bill and say take it or leave it is not going to work in this caucus."

The tax rate and licensing fee proposed for table games was another unilateral move by House Democrats. Senate Republican proposals had called for much lower tax rates, saying a high rate would deter casinos from adding table games.

House Speaker Keith McCall, D-Carbon County, noted there was significant doubt about how much revenue the arts ticket tax and small-games tax would raise.

"Our members said, 'Is it really worth taking on those two things ... when in fact we can increase the tax on table games to 34 percent and pay for it all?'" he said.

The revisions did nothing to garner House GOP support. Republican Leader Sam Smith, R-Jefferson County, said the revisions would hit more Pennsylvanians with a tax increase, making it tantamount to an increase in the state's income or sales tax.

Senate Republican leaders made it clear earlier Thursday that they would consider any changes to the revenue package as a change to the agreement that might take the budget discussions back to square one.

"We have agreed to things we would otherwise not have agreed to [as part of the agreement]. ... For them to just take what was easy for them and not to lift the parts that are unpleasant or uncomfortable for them and expect us to do both ... is not adherence to the deal," said Senate Majority Leader Dominic Pileggi, R-Delaware County.

Rendell urged Senate Republicans to be open-minded, arguing that any changes in the House would be "at the margins" of the $1.2 billion tax package.

"To say, 'This wasn't the dotted I, crossed T of the deal, so we're going to take our toys and go home'... that would be inexcusable," said Steve Crawford, Rendell's chief of staff.

But Corman said, "Where I come from, a handshake is a handshake."