WASHINGTON (Reuters) - Republicans in the House of Representatives on Wednesday threatened to subpoena five White House aides in their investigation of Solyndra LLC, the failed solar panel maker that received more than $500 million in federal loan guarantees.

House Energy and Commerce Committee Chairman Fred Upton and Cliff Stearns, the lawmaker who has led the probe, said the committee would vote on Friday to subpoena the staffers unless the White House makes them available to testify.

They are Kevin Carroll, Kelly Colyar and Fouad Saad of the Office of Management and Budget, Heather Zichal, a top White House energy official, and Aditya Kumar, who worked for former White House Chief of Staff Rahm Emanuel and now works for Vice President Joe Biden.

A White House spokesman accused Republicans of dragging out their investigation to try to score political points.

"Despite no evidence to support their accusations - or perhaps because of it - the committee continues to demand more materials with no real relevance to the Energy Department's decision-making on the loan," said Eric Schultz.

The committee has previously issued subpoenas for White House documents related to the department's $535 million loan guarantee to Solyndra, which filed for bankruptcy last year and was raided by the FBI.

The California company's failure has been an embarrassment for the White House after President Barack Obama visited the firm in 2010. His administration has promoted clean energy as one way to create jobs.