At a House hearing marked by partisan rancor, Energy Secretary Steven Chu disputed Republicans' allegations that politics played a role in his decision to approve a loan guarantee to now-bankrupt solar energy company Solyndra.

E-mails obtained and released by Republican committee members have suggested that there was some disagreement within the Obama administration about Solyndra's economic viability.  Some lawmakers have suggested that the White House pressured the Dept. of Energy to take Herculean steps to save the foundering company, which declared bankruptcy late this summer.

Chu told the House Energy and Commerce Committee's oversight and investigations subcommittee at a Nov. 17 hearing that DOE's decision to offer the company a $535-million loan guarantee “absolutely…was made only on the merits.”

He said he took full responsibility for the decision to approve the loan guarantee, but noted that the decision spanned two administrations and was made only after two years of “rigorous technical, financial and legal due diligence.”

But Republican lawmakers,  particularly subcommittee Chairman Cliff Stearns (R-Fla.) and Joe Barton (R-Texas), questioned Chu’s management of the loan program. They grilled him about the degree to which he was pressured by the White House to make sure the company—viewed as a centerpiece of President Obama’s clean-energy agenda—succeeded.

Stearns also raised the issue of the loan-guarantee program's overall viability. Two of the first three firms to receive loans under Chu’s leadership have gone bankrupt, including Solyndra. Stearns said, “If Solyndra really is a litmus test, we have a much bigger problem on our hands.”

Democrats criticized the way the Republicans were conducting the investigation, which was launched this spring.