(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.

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