The White House on Friday all but refused to turn over the documents House Republicans have subpoenaed on bankrupt solar firm Solyndra, firing off a letter saying the request would put an “unreasonable burden on the president’s ability to meet his constitutional duties.”

The feisty response appears to set up a clash between congressional investigators and the White House over the sprawling probe into Solyndra’s finances and the administration’s involvement in the decision to provide the struggling company a $528 million loan with taxpayer money.