The White House is rebuffing a subpoena from House Republicans seeking documents on the solar panel company, Solyndra, which received a half-a-billion-dollar federal loan guarantee then went bankrupt.

White House Counsel Kathryn Ruemmler responded Friday to two Republicans on the House Committee on Energy and Commerce, one day after the subpoena was authorized on a party-line vote.

In her correspondence, Ruemmler said the request was driven more by partisan politics than a legitimate effort to conduct a responsible investigation. She described the scope of the investigation as “burdensome and intrusive,” saying it encroached on longstanding and important Executive Branch confidentiality interests.

Ruemmler said none of the more than 85,000 pages of documents produced to date evidences any favoritism to political supporters or wrongdoing by the White House.

She did say officials remain willing to work with the committee to accommodate its legitimate oversight interests in a balanced manner. The letter was written to Fred Upton, the committee chairman, and Cliff Stearns. In response, Upton said the request for the communications was reasonable and would help answer questions about the failed loan.

Last week, the White House ordered an independent review of U.S. Energy Department loans in the wake of the Solyndra issue. Officials say a former Treasury Department official, Herb Allison, will lead the 60-day process.

Solyndra received the loan in 2009. In July, top executives testified to Congress that the company was prospering. But a few weeks later, the California-based company laid off more than 1,000 workers and filed for bankruptcy. The firm said it could not cut costs fast enough to keep up with Chinese solar panel makers.

One lawmaker compared the lost loan funding to a train robbery.

The case has been embarrassing for the Obama administration, which has held up the company as an example of desirable “green” technology and job creation.

Republicans have questioned whether Solyndra received the loans unfairly because one of its key investors was also a major donor to the 2008 Obama presidential campaign.