On the eve of serious negotiations to bridge the state's historic budget gap, the Republican leader of the Senate told lawmakers of his party that he would campaign against anyone who joins Democrats in voting for tax increases.

Sen. Jim Brulte of Rancho Cucamonga said Tuesday at a meeting of Republican legislators that he would go to their districts to debate them on the issue of tax increases and raise money for their opponents.

He showed them a sample of a direct mail advertisement that could be sent to voters in their districts if they crossed party lines on the budget.

Brulte's comments set off a tempest inside the Capitol Wednesday, with Democratic leaders accusing Brulte of closing off the possibility of compromise and even some Republican lawmakers grumbling privately about heavy-handedness.

Assembly Speaker Herb Wesson, D-Culver City, called Brulte's remarks "ridiculous."

"You bring your caucus together by explaining what the problem is. ... You don't do that by threats," Wesson said. "We would never do that in my caucus."

Brulte denied that his remarks were intended as threats.

"I let people know that I feel so strongly about this that I might actually do something I normally don't do, which is argue against the election of an incumbent Republican," he said. "This isn't a threat. I have a right to endorse candidates."

The incident underscored the polarized atmosphere as lawmakers convened a special budget-writing conference committee Wednesday to deal with an estimated $38.2 billion state budget shortfall through the fiscal year that starts July 1. The budget must be passed by a two-thirds majority in each house of the Legislature. This year, that means two Republicans in the Senate and six in the Assembly would have to join majority Democrats in approving the spending plan.

Gov. Gray Davis has proposed about $8 billion in tax increases to pay off part of the deficit and shift some state responsibilities to counties. Republicans leaders say they won't sign off on any tax hikes. But some GOP lawmakers have said privately that they might go along with temporary increases coupled with long-term efforts to rein in future spending.

Brulte made his remarks at a joint meeting of the Assembly and Senate Republican caucuses at the California Chamber of Commerce in downtown Sacramento. Members were being introduced to a candidate for an Assembly seat that will be open in 2004.

Brulte gave a presentation on how Republicans believe the budget can be balanced without new taxes. He showed a videotape of a speech he made on the Senate floor about the budget. And he warned that he would take the debate to the districts of lawmakers who broke ranks.

Some saw Brulte's tactic as evidence that he's worried about party unity.

"I think the fact that they have to sort of threaten the other Republicans on the tax issue kind of tells me they don't have that much confidence in their position," said Senate President Pro Tem John Burton, D-San Francisco.

But others interpreted it as a warning to Democrats that this year they won't be able to entice a handful of renegade Republicans to vote for the budget, as has happened in recent years.

"It was an attempt to keep us together as a team at crunch time," said Assemblywoman Lynn Daucher, R-Brea.

Assembly GOP leader Dave Cox of Fair Oaks said Brulte's comments were prompted by newspaper reports that some Republicans could be wavering. But Cox said his caucus is solidly behind the no-taxes pledge.

Cox, while not criticizing Brulte's strategy, distanced himself from it, saying he would not campaign against incumbents who defied the leadership.

Assemblyman Joe Canciamilla, D-Pittsburg, part of a group of moderates from both parties seeking common ground, called Brulte's remarks "extremely damaging."

"It intimidates members and it keeps them from being open about how to come to a real solution," he said.