Arizona Rep. Russell Bowers asks a question as Arizona House members receive mandatory sexual harassment and other ethics issues training on the House floor at the Capitol, on Jan. 9, 2018, in Phoenix.
CNN  — 

Rusty Bowers, a Republican and Arizona state House speaker, will testify at a Tuesday hearing focusing on former President Donald Trump’s pressure on state officials to overturn Joe Biden’s victory in 2020, a source familiar with the matter told CNN earlier Saturday.

Bowers will join Georgia’s election officials — Brad Raffensperger and Gabe Sterling — who will be part of a panel before the January 6 committee detailing Trump’s campaign to force states to overturn their certified election results.

Bowers, who supported Trump’s reelection bid in 2020, refused to bow to intimidation and attempts to get him to back efforts in the legislature to decertify Biden’s victory in Arizona.

He previously described how Trump and the then-President’s lawyer Rudy Giuliani called him after the 2020 election to convince him to somehow involve the legislature in the state’s certification process before sending its presidential electors to Congress.

This past year, Bowers also shot down some of his fellow Arizona Republicans’ more extreme election ideas, including a resolution of mostly debunked claims of fraud that called for the election results to be set aside in three Arizona counties.

In February, the Republican speaker used a parliamentary maneuver to effectively doom a GOP bill which would have overhauled elections in Arizona, including by giving the state legislature the power to reject election results it didn’t like.

Tuesday’s hearing will be the fourth this month for the January 6 committee.

Rep. Zoe Lofgren, a California Democrat, later confirmed CNN’s reporting about Bowers testifying during an interview with CNN’s Jim Acosta on “Newsroom.”

“That’s my understanding,” Lofgren said, adding she wanted to hear “the truth” from those testifying.

“These individuals are Republicans. They voted for Trump. They are, you know, supported him,” she said. “But they wouldn’t do illegal things that he asked them to do. So we expect to hear in some detail about the pressure that was placed on them and why they were true to the law instead of the pressure.”

Raffensperger, Georgia’s Republican Secretary of State, resisted Trump’s efforts during an infamous January 2021 phone call to pressure him to “find” the votes necessary for the then-President to win Georgia. Last month, he fended off a Trump-backed primary foe as he seeks a second term in office.

Sterling, Raffensperger’s deputy, publicly pleaded in December 2020 for Trump to denounce the harassment and threats officials and election workers had faced.

This story has been updated with additional background information.

CNN’s Veronica Stracqualursi and Sarah Fortinsky contributed to this report.