The Obama administration continued to pump millions of taxpayer dollars into Solyndra, a solar-panel manufacturing firm, even though the White House knew it would be cheaper to allow the already troubled firm to go bust, a new congressional report concludes.

Calling the now-bankrupt company 'the poster child" of President Obama's signature economic policy promoting green energy, the Republican-led investigation found that top administration officials hastily approved a loan and later restructured it, despite mounting evidence Solyndra was not financially stable. The government gave the California company a $535 million loan in 2009.

The firm, which once served as campaign-style backdrop for Obama's green-energy push, never found a strong market for its solar panels and abruptly shut down in 2011, laying off 1,100 workers and leaving taxpayers on the hook for nearly the entire value of the $535 million loan.

House Speaker John Boehner on Thursday called on White House Chief of Staff Jacob Lew, who oversaw the Solyndra loan, to defend the decision to continue funding a company that was already losing money.

"I think Mr. Lew and the White House owe the American people an explanation as to why they squandered hundreds of millions of dollars," Boehner said.

Boehner, R-Ohio, and other Republicans believe the loan was later restructured so that a group of private investors that included a top Obama campaign contributor, George Kaiser, would be repaid before the Treasury was if Solyndra defaulted.

The 147-page report was assembled by Republicans on the House Energy and Commerce Committee after months of inquiry. Committee Democrats on Thursday rebutted the report, strongly denying that political considerations played any role in the restructuring of the Solyndra loan.

The Republican report, Democrats said, "does not substantiate these inflammatory allegations" and "cherry picks facts, distorts the record, and omits exculpatory evidence to create a misleading insinuation that political contributions influenced White House actions."

Democrats point out that Solyndra failed in part because of competition from the Chinese, who helped push down the cost of solar panels by more than 70 percent.

The Republican report revealed potentially damaging emails, including one in which Solyndra CEO Christian Gronet told his principle investors about the September 2009 government loan by saying, "The Bank of Washington continues to help us!"

The report goes on to say that even as mounting evidence underscored Solyndra's unhealthy financial situation, Department of Energy officials "remained determined" to push through a second loan guarantee, that only later was cancelled.

"Solyndra should serve as a cautionary tale on how political pressures and an administration's desire to create political events to highlight its policies can result in poor decision making," the report concluded.

Republicans seized on Solyndra and several other failed green-energy companies that received government funding as evidence that Obama has been a poor steward of tax dollars who put political campaign contributors ahead of taxpayers.

Ryan Williams, a spokesman for Republican presidential candidate Mitt Romney, sent an email to reporters headlined simply, "Ugh."

Williams quoted an August 2011 email exchange between Obama advisor Stephanie Cutter and Deputy Communications Director Dan Pfeiffer after he informed her that Solyndra was about to go under.

"This," Pfeiffer wrote, "is going to be a real pain."