The Senate Homeland Security and Governmental Affairs Committee on Wednesday voted to subpoena Blue Star Strategies — a company connected to the Ukrainian natural gas firm Burisma Holdings -- as part of the panel’s investigation into Hunter Biden’s role on the board of the firm.

The committee voted on party lines, 8-6, to subpoena Blue Star Strategies, the consulting firm linked to Biden and Burisma. Sen. Mitt Romney, R-Utah, who sits on the committee, voted with Republican colleagues to approve the subpoena.

GOP SENATOR PLANS TO SUBPOENA CONSULTING FIRM LINKED TO HUNTER BIDEN, BURISMA

Committee Chairman Ron Johnson, R-Wis., announced earlier this year his plans to subpoena Blue Star Strategies for records to review potential conflicts of interest in Biden's role on the board of Burisma, and whether individuals at the firm improperly used the relationship with 2020 Democratic presidential candidate Joe Biden's son to “influence” U.S. government agencies.

The subpoena would cover records dating back to January 1, 2013, regarding their work for Burisma Holdings, or individuals associated with Burisma’s founder, Mykola Zlochevsky. He also wants Blue Star CEO Karen Tramontano and Chief Operating Officer Sally Painter for depositions.

But the head of Blue Star Strategies penned a letter to Johnson and Republicans on the committee on Wednesday morning, highlighting their past cooperation with the panel's requests, and questioning why they would subpoena further documents.

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"At every opportunity we have indicated tot he Committee that it is our intention to cooperate,” Karen A Tramontano, the co-founder and CEO of Blue Star wrote to the committee. “Therefore, we are puzzled, despite our willingness to cooperate, why the committee is proceeding to vote on a subpoena.”

Tramontano went on to request that the committee “take into consideration that we have eagerly cooperated to date and have every intention to continue to do so in the future.”

A committee spokesperson told Fox News Wednesday that "a bipartisan group of committee members suggested that we subpoena Blue Star Strategies, so we authorized that today."

"The fact is Blue Star has delayed our efforts for more than five months, and even refused to let our staff speak to their attorney until last week--despite the fact that he was speaking with the Ranking Member's staff," the spokesperson told Fox News. "Their only real efforts came after we noticed this markup, and we know even those have been woefully incomplete."

The spokesperson added that "the American people deserve to know the extent to which the U.S.-based, Democrat-led consulting company leveraged its connections within the Obama administration to try to gain access to and influence U.S. government agencies on behalf of its corrupt client, Burisma."

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"We are looking forward to receiving a full response to all of our questions," the spokesperson said.

Hunter Biden joined Burisma in April 2014 and, at the time, reportedly connected the firm with Blue Star to help the Ukrainian natural gas firm fight corruption charges. At the time of Biden’s work on the board, then-Vice President Joe Biden was running U.S.-Ukraine relations and policy for the Obama administration.

Biden’s work for Burisma received heightened scrutiny amid Trump’s impeachment last year.

Trump, during his now-infamous July 25, 2019 phone call with Ukrainian President Volodymyr Zelensky, pressed for Kiev to look into the elder Biden's role pressing for the ouster of a Ukrainian prosecutor who had been investigating the founder of Burisma. Allies of the now-front-running Democratic presidential primary candidate maintain that his intervention at the time had nothing to do with his son, but rather was tied to corruption concerns. According to reports, by the time of Biden's intervention, the Burisma probe had been dormant.

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Trump's pressure campaign against Ukraine prompted a whistleblower complaint, and, in turn, the impeachment inquiry.

The president’s request came after millions in U.S. military aid to Ukraine had been frozen, which Democrats cited as a quid pro quo arrangement. Trump was acquitted on both articles of impeachment—abuse of power and obstruction of Congress—in February.

The subpoena comes amid a joint investigation led by Johnson and GOP Sens. Lindsey Graham, chairman of the Senate Judiciary Committee, and Chuck Grassley, chairman of the Senate Finance Committee.

Johnson, Graham and Grassley requested information in December related to potential conflicts of interest and political influence by Ukraine, including Burisma Holdings.