UPDATE: Gov. Kate Brown has authorized Oregon State Police to bring back Senate Republicans after they walked out on Thursday over a controversial climate bill.

Brown issued the following statement:

“After many hours of well-intentioned, respectful negotiations on Wednesday, the Senate has come to an impasse. The Senate Republicans have decided to abandon their duty to serve their constituents and walk out. The Senate Democrats have requested the assistance of the Oregon State Police to bring back their colleagues to finish the work they committed to push forward for Oregonians. As the executive of the agency, I am authorizing the State Police to fulfill the Senate Democrats’ request. It is absolutely unacceptable that the Senate Republicans would turn their back on their constituents who they are honor-bound to represent here in this building. They need to return and do the jobs they were elected to do.”

SALEM, Ore. (KGW) -- Senate Republicans have walked out a second time during this legislative session, this time in protest over a cap-and-trade bill to push Oregonians to lower pollution by ditching fossil fuel engines.

"In a few moments, I will not be in Oregon,” Sen. Cliff Bentz of Ontario told the Oregonian just after 7 a.m.

RELATED: GOP SENATORS IN OREGON POISED TO WALK OUT OVER CLIMATE BILL

In a prepared statement, the GOP said Democrats failed to follow a procedural agreement made after an earlier walkout. The cap-and-trade bill should be referred to voters, they said.

"We will not stand by and be bullied by the majority party any longer," the statement said. "Oregonians deserve better. It’s time for the majority party to consider all Oregonians – not just the ones in Portland.”

Oregon Gov. Kate Brown said Wednesday she's willing to extend the legislative session and mobilize the state police if Senate Republicans followed through with a threat to block a vote on a sweeping climate plan.

MORE: GOV. BROWN SAYS SHE'LL USE POLICE IF GOP WALKS OUT

"I am prepared to use all resources and tools available to me as Governor to ensure that Oregonians are being served by their leaders," she said in a statement. "I am in close communication with Oregon State Police and my office is making preparations for a special session."

Senate Republican Leader Herman Baertschiger, Jr., responded to the governor's threats, saying that Democrats' climate proposals threaten business and the livelihoods of rural communities.

"Walking out is part of the conversation because the governor is not willing to move on her position on the bill," said Baertschiger, from Grants Pass. "She is only representing Portland and the environmental community, not rural Oregonians."

Democrats in Oregon control both the House and the Senate. The GOP has previously used walkouts as a way to slow the legislative process.

Republicans walked out of the Senate earlier this session in protest of a school funding tax package, denying the chamber enough lawmakers to continue with a vote. The sergeant-at-arms of the Oregon Senate was ordered to search the Capitol for Republican senators who were refusing to attend. The standoff lasted four days, until the governor struck a deal to table legislation on gun control and vaccine requirements.

Sen. Brian Boquist, a Republican from Dallas, pushed back against the governor's threats to mobilize the state police if a second walkout occurs.

"If you send the state police after me," he told Senate President Peter Courtney, "Hell's coming to get you."

Boquist re-iterated his stance with KGW's Pat Dooris. He said if police come, they should "send bachelors and come heavily armed. I'm not going to be a political prisoner in the state of Oregon."