(CNN) Republican Sen. Mitt Romney of Utah plans to vote in favor of a subpoena as part of the Senate Homeland Security and Governmental Affairs Committee's investigation into Burisma, a key decision that could advance the GOP investigation into the Ukrainian energy firm tied to Joe Biden's son.
Romney had raised concerns that the investigation had the appearance of a political probe aimed at hurting Joe Biden, who has reemerged in the 2020 primary as the Democratic front-runner to take on President Donald Trump. But Romney's office said Friday that Committee Chairman Ron Johnson, a Wisconsin Republican, alleviated his concerns of a "public spectacle," so he agreed to back the subpoena to a public affairs consultant who worked with Burisma, the Ukrainian energy firm that hired Biden's son Hunter.
"Senator Romney has expressed his concerns to Chairman Johnson, who has confirmed that any interview of the witness would occur in a closed setting without a hearing or public spectacle," Romney spokeswoman Liz Johnson said. "He will therefore vote to let the Chairman proceed to obtain the documents that have been offered."
Romney's announcement is significant now Johnson likely has enough support to issue subpoena when his committee votes on Wednesday, with Republicans holding an 8-6 advantage on the panel.
Johnson is planning to issue a subpoena for records to Andrii Telizhenko, the former consultant for public affairs firm Blue Star Strategies that worked with Burisma. Johnson says Telizhenko, a Rudy Giuliani ally who worked at the Ukrainian embassy in 2016 and has spread conspiracy theories that Ukraine meddled in the election in 2016, has expressed a willingness to cooperate with the Senate probe.
Trump and his allies have repeatedly made unfounded and false claims to allege that the Bidens acted corruptly in Ukraine.
The Senate Republican investigations into Ukraine come amid Biden's surge in the 2020 Democratic presidential campaign, which Democrats have derided as a partisan attempt to tarnish Trump's potential general election opponent.
Johnson argued Thursday the "timing of this is coincidental" with the presidential race. Asked why GOP didn't probe the matter when Biden was in office, he told CNN: "We didn't have all the information, I mean you start investigating things when things come to light.
While Johnson has insisted the probe Burisma was not about the campaign or the Bidens, but he also said earlier this week that the information he was seeking would be of interest to primary voters.
Johnson and Senate Finance Chairman Chuck Grassley, an Iowa Republican, have sent a number of requests for documents to government agencies related to Ukraine, Burisma and Joe and Hunter Biden. Johnson said he could potentially release an interim report of his findings in the next month or two.
Trump, meanwhile, said in a Fox News interview this week with Sean Hannity that he would make Ukraine a "major issue in the campaign" if Biden is the Democratic nominee.
Sen. Gary Peters of Michigan, the top Democrat on the panel, opposed Johnson's subpoena last month, which forced him to put the issue to the full panel to issue the subpoena. Peters has declined to say whether the probe is political or not, but he's argued the committee has more pressing issues to tackle.
Sensing the potential hurdle with Romney and other Republicans, Johnson this week briefed Republicans on his committee in a classified setting on the investigation to try to address their concerns.
Romney had warned that the investigation had the appearance of looking political by targeting the Bidens in an election year, and suggested the committee should be working on other issues.
"There's no question but the appearance of looking at Burisma appears political," Romney said Thursday. "And I think people are tired of these, these kind of political investigations, and I would hope that there's something of significance that needs to be evaluated that would be done perhaps the FBI or some other agency, although it's not as political as perhaps a committee of our of our body."
Romney added: "We also have a lot of work to do on matters that are not related to Burisma. We probably ought to focus on those things."
This story has been updated with additional developments.