OLYMPIA — Minority House Republicans said yesterday the price of their cooperation in helping pass an $8 billion transportation finance plan is that Democrats drop their plan for $500 million in general-government tax increases.

House Democrats rejected the offer, leaving the future of the 9.5-cent-a-gallon gas tax increase very much in doubt. That tax increase would help finance transportation projects over the next 16 years.

"We don't believe in pitting kids against roads," and the operating and transportation budgets will remain separate issues, said House Speaker Frank Chopp, D-Seattle.

"I don't know if it's block or bluff," but Republicans will have to decide whether they're prepared to kill crucially needed transportation improvements, said House Transportation Chairman Ed Murray, D-Seattle.

Chopp and the House Democrats, as well as Democratic Gov. Christine Gregoire, have demanded that the Republicans help pass the transportation tax so that it is less likely to become a political football during the next election.

Chopp and Murray accused Republicans of turning their backs on the usual bipartisanship on transportation issues and "reneging on a commitment to pass needed safety and freight improvements for our roads and highways." They said they were prepared to let the measure die if Republicans refuse to help.

Chopp said only "30-some" House Democrats are prepared to take the politically risky vote, meaning between 12 and 18 Republicans must pair with them.

It takes 50 votes to pass the tax bill in the 98-member House.

Wednesday, the Senate approved a transportation package, 26-22. Seven Republicans joined 19 Democrats to pass the plan.

Chopp said he'll schedule a House vote today or tomorrow.

House Republican leaders Bruce Chandler of Granger, Mike Armstrong of Wenatchee and Doug Ericksen of Bellingham said it's the majority party's duty to pass legislation, and that Chopp has never directly asked for help on the transportation package.

They said the GOP is willing to help. "If they work with us on adopting a sustainable, no-new-taxes general-fund budget, we will work with them to adopt a comprehensive transportation package," Chandler said.

The state's economic recovery is fragile and legislators shouldn't resort to taxes to balance the $28 billion main budget, he said. Chandler said some of his members would vote for the transportation plan even if the Democrats don't meet their demands.

Chopp said the Democrats aren't able to back down from the tax increases for the main budget. The $500 million package, including "sin tax" increases on cigarettes and liquor, an estate tax and other revenue bills, replaces revenue that the state Supreme Court struck down.