Topeka ? Republicans in the Kansas House threatened Thursday to block an important unemployment bill favored by business leaders and GOP Gov. Sam Brownback’s administration unless the measure also prohibits labor unions from financing political activities with funds deducted from members’ paychecks.

House Commerce and Economic Development Committee Chairman Anthony Brown said his chamber can’t accept provisions in the unemployment bill increasing businesses’ costs without the restriction on unions. The Eudora Republican is his chamber’s lead negotiator in talks with the Senate over the unemployment bill.

That measure is considered vital because it allows Kansas to repay $171 million in loans made to it by the federal government last year to cover benefits for unemployed workers, as well as up to $8 million in interest costs. Without it, Kansas Department of Labor officials said, the state will face federal penalties.

The House has approved what supporters call the “paycheck protection” restrictions on unions, but the bill has stalled in the Senate. The lead Senate negotiator, Commerce Committee Chairwoman Susan Wagle, a Wichita Republican, supports it, but Senate GOP leaders don’t think it will pass their chamber.

The three senators and three House members negotiating over the unemployment bill convened for about 10 minutes Thursday before Wagle declared their talks at impasse and adjourned them indefinitely.

“Without the policy piece of paycheck protection, it won’t happen,” Brown told Wagle and her colleagues. “The House is prepared to walk away.”

Wagle replied, “That would be pretty bad.”

But Brownback didn’t express concern about the dispute, refusing to take sides, though he said legislators need to pass the unemployment bill.

“Let’s see what they come up with,” he told reporters. “Let’s see what it takes to get it through the legislative process.”

The state imposes a tax on employers to finance benefits for unemployed workers. Claims for benefits spiked in the Great Recession, depleting the state’s unemployment fund last year and triggering automatic tax increases for employers.

This year’s unemployment tax bill would raise an additional $236 million over three years to pay back the federal government, including interest. State law now prevents Kansas from paying interest.

The House’s version of the bill doesn’t include the same tax increases for 2012, 2013 and 2014, but under its plan, rates would suddenly jump in 2015 to replenish the unemployment fund. Along with Brownback’s administration, the Kansas Chamber of Commerce favors the Senate’s version.

“No state has defaulted on their interest payments,” said Deputy Labor Secretary Kathie Sparks. “If they pass nothing, we’ve got serious problems.”

Brown’s push for the paycheck deduction proposal is in sharp contrast to comments he made in March, when the measure stalled in the Senate. Then, he said it wouldn’t pass this year, promised to work to smooth its passage next year and described any attempt to do exactly what he’s trying now as “a far stretch.”

Such brinksmanship sometimes occurs as lawmakers rush to wrap up the year’s business, tying up measures all parties agree are destined for passage. Thursday was the 84th day of the Legislature’s annual session, out of 90 scheduled.

Backers of the paycheck deduction proposal said they’re trying to protect workers from being forced to contribute to candidates or political activities they don’t support.

Critics see the proposal as an attempt by many Republicans to hinder fundraising by unions, which are an important source of support for Democrats. Opponents also contend there’s no need for the legislation because paycheck deductions are voluntary, and they say workers will be hurt if it’s harder for them to pool their resources.

“That’s all we ever want, to have a voice,” said Andy Sanchez, a lobbyist for the Kansas AFL-CIO. “This will take away that.”

Emotions have run high over the legislation.

When the House voted on the measure in late February, several dozen union members in the gallery shouted at lawmakers to vote against it before they were escorted out. Speaker Mike O’Neal, a Hutchinson, a Republican who supported the bill, later banned one labor lobbyist who participated from the gallery for the rest of this year’s session.

House Republican leaders and their aides said union members shouted obscenities and vulgar epithets at female GOP lawmakers and staff before the vote, but union leaders denied the claims. After the state GOP put out a statement decrying the “street tactics” of “union thugs,” hundreds of union members held a Statehouse rally to protest the bill.