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The White House on Friday all but refused to turn over the documents House Republicans have subpoenaed on bankrupt solar firm Solyndra, firing off a letter saying the request would put an "unreasonable burden on the president's ability to meet his constitutional duties."

The feisty response appears to set up a clash between congressional investigators and the White House over the sprawling probe into Solyndra's finances and the administration's involvement in the decision to provide the struggling company a $528 million loan with taxpayer money.

White House Counsel Kathryn Ruemmler, in her letter, scolded GOP lawmakers for demanding more documents, noting the Obama administration has already turned over 85,000 pages of documents in the course of their investigation. Without explicitly refusing to comply with the subpoena, Ruemmler repeatedly described the order as "overbroad."

"The Committee's extremely broad request for documents -- now a subpoena -- is a significant intrusion on Executive Branch interests," she wrote, saying she can only conclude the subpoena was "driven more by partisan politics than a legitimate effort to conduct a responsible investigation."

Rep. Fred Upton, R-Mich., chairman of the House Energy and Commerce Committee, questioned what the West Wing was trying to "hide" in a response late Friday.

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"We have been reasonable every step of the way in this investigation, and it is a shame that the Obama administration and House Democrats continue to put up partisan roadblocks to hide the truth from taxpayers," he said. "Now, we need to know the White House's role in the Solyndra debacle in order to learn the full truth about why taxpayers now find themselves a half billion dollars in the hole. The White House could have avoided the need for subpoena authorizations if they had simply chosen to cooperate."

Though the White House has turned over thousands of documents, Republicans say the administration has not provided everything they've requested. The House Energy and Commerce Committee voted Thursday to subpoena, and the subpoenas went out late Thursday to the White House and office of the vice president.

"Unfortunately, we had to take this step after the White House has continued to slow walk the production of documents necessary for this investigation by only releasing selected documents and records," Rep. Cliff Stearns, R-Fla., chairman of the House panel investigating the matter, said in a statement.

The subpoena called on the White House to produce "all documents referring or relating in any way" to the Solyndra loan guarantee, as well as to investors in the company and to the company's financial condition.

The White House said in the letter Friday that "there is no basis for such a broad request," claiming the administration has acted in "good faith" to accommodate the requests so far.

Ruemmler said the White House is "willing" to continue working with the committee but suggested they "negotiate the scope" of the documents they want produced.

As Republicans pressed the White House for more information, new bankruptcy court documents also revealed that Solyndra executives were paid quarterly bonuses earlier this year worth up to $60,000 apiece.

Fox News' Ed Henry contributed to this report.