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The White House pressed federal officials in 2009 to review a massive loan to a now-bankrupt solar panel maker despite warnings from within the administration that it was "not ready for prime time," newly released emails show ahead of Wednesday's Republican-led hearing on the controversy.

Solyndra's collapse earlier this month left taxpayers on the hook for $528 million. A House Energy and Commerce subcommittee on Wednesday will probe how the loan was approved, at a hearing that's part of a seven-month investigation.

Details about the White House's push for the loan continued to surface Tuesday night, with reports citing email exchanges in the weeks leading up to the administration's announcement of the loan in September 2009.

The emails, first reported by The Washington Post and ABC News, have been confirmed by Fox News.

The emails show White House officials repeatedly checking with the Office of Management and Budget on the progress of its review of the loan ahead of a high-profile groundbreaking for the company's new factory. Vice President Biden was set to announce the loan approval at the event, and emails show his office checking up on the review process.

One email from a budget official referred to "the time pressure we are under to sign-off on Solyndra," the Washington Post reported, which quoted another email complaining of "rushed approvals."

One exchange showed a budget analyst in March 2009 warning the deal was "not ready for prime time," ahead of the Biden announcement.

But the White House denied that it was trying to influence the result of the financial reviews, and it has defended the federal loan.

"This loan guarantee was pursued by both the Bush and Obama administrations," White House spokesman Eric Schultz said. "The Department of Energy's overall portfolio of investments -- which includes dozens of other companies, continues to perform well and is on pace to create thousands of jobs."

Schultz again defended the White House later Tuesday in response to the reports on the emails.

"Private sector investors -- who put more than $1 billion of their own money on the line -- also saw great potential in the company," Schultz said.

House Republicans are eager to find out at the hearing why the Obama administration continued to promote and refinance the loan guarantees. The administration guaranteed up to $535 million, and lent $528 million.

“Many of us think he was trying to get the money out the door perhaps for political reasons, and in the end taxpayers lost over half a billion dollars,” said Rep. Cliff Stearns, R-Fla., chairman of the House Energy and Commerce Subcommittee on Oversight and Investigations.

Asked if someone should be fired over this, Stearns told Fox News, "I do."

In an SEC filing in March 2010, a year after the California-based Solyndra got the loan guarantees but before the refinancing, independent auditor PricewaterhouseCoopers said several negative financial factors "raise substantial doubt about its ability to continue as a going concern."

Still, two months later, Obama went to Solyndra’s solar panel plant and touted green energy and the stimulus.

“The true engine of economic growth will always be companies like Solyndra,” Obama said at the time.

But this summer, after CEO Brian Harrison told members of Congress that “Solyndra’s financial condition was improving," Energy Department officials let lawmakers know that the company was facing “decreased revenues.”

“Obviously there was duplicity here because (the Energy Department) was on the board of Solyndra monitoring what happens, and eventually they were concerned enough that they sent in their own inspector team and the FBI a couple of days ago because they suspect criminality,” Stearns said.

In addition to raiding the company's headquarters, the FBI also interviewed Solyndra executives at their home following the company's bankruptcy announcement. The FBI has not said what the investigation is focused on but it is widely believed to be linked to the bankruptcy.

"While we are disappointed by this particular outcome, we continue to believe the clean energy jobs race is one that American can, must and will win," White House spokesman Schultz said. "The question we, as a country, have to ask ourselves is: are the jobs of the future going to created here in the United States or elsewhere?"

Solyndra, whose technology relied on a tube that could soak up sunlight from many different angles, producing energy more efficiently and using less space, became the first company to get a loan guarantee through Obama’s 2009 economic stimulus program. The government later restructured the terms of the loan.

When the Energy Department rejected Solyndra’s request for a second refinancing to get additional financing from private investors, the company filed for bankruptcy.

Congressional investigators have issued subpoenas for documents from the White House Office of Management and Budget concerning Solyndra. In particular, they’re seeking communications between the White House and Solyndra and its investors to determine whether politics played a role in the approval of the loan.

Harrison, the Solyndra CEO, and another company executive were supposed to testify Wednesday at the hearing, but Stearns says they’ve asked for another week to prepare. Still, lawmakers will hear from Obama administration officials, including Jeffrey Zients, deputy director of the White House budget office, and Jonathan Silver, executive director for the Energy Department’s loans program.

“We had a sense Solyndra was a bad bet from the beginning and its failure raises significant red flags for the entire loan guarantee program,” Stearns and Rep. Fred Upton, R-Mich., chairman of the Energy and Commerce Committee, said in a statement. “It is not the role of government to pick winners and losers in the market.”

“With taxpayers potentially on the hook for this half-billion dollar bust, it’s time to sound the alarm about the remaining $10 billion in loan guarantees set to expire Sept. 30,” they said.

Fox News' Molly Henneberg and The Associated Press contributed to this report.