An investigation by the House Oversight and Government Reform Committee shows that the White House pressured the Environmental Protection Agency to refuse a request by the state of California to regulate greenhouse gas emissions. In December, EPA denied a California petition, or waiver, that would have allowed the state to set standards for greenhouse gas emissions from vehicles. Under the Clean Air Act, only the federal government may regulate vehicle emissions; but California — and only California — may request permission to set up its own regulatory scheme. If EPA grants California permission (as it had with every request prior to this one), other states may choose between California's program and the federal program. At least 15 other states were prepared to follow California's plan, if permitted. When EPA announced the denial, Administrator Stephen Johnson claimed the decision was his alone. But the denial of the California petition had the White House's fingerprints all over it. Last fall, Vice President Dick Cheney met with executives from Ford and Chrysler who urged him to deny the request, according to the investigation. The White House Council on Environmental Quality (along with the Transportation Department) lobbied U.S. representatives and governors urging them to oppose California's efforts. At the time of the announcement, no hard evidence existed to refute Johnson's claim that he, and not the White House, was responsible for the denial. The deposition of an EPA assistant administrator, taken by the House investigators, begins to shed some light on who was actually responsible for the decision. Committee investigators heard from EPA Associate Deputy Administrator Jason Burnett, whose carefully chosen words nonetheless cast doubts on Johnson's claim that the Dec. 19 decision to deny the waiver was his alone: According to Mr. Burnett, Administrator Johnson's preference for a full or partial grant of the waiver did not change until after he communicated with the White House about the matter. When asked by Committee staff "whether the Administrator communicated with the White House in between his preference to do a partial grant and the ultimate decision" to deny the waiver, Mr. Burnett responded: "I believe the answer is yes." When asked "after his communications with the White House, did he still support granting the waiver in part," Mr. Burnett answered: "He ultimately decided to deny the waiver." Mr. Burnett also affirmed that there was "White House input into the rationale in the December 19th letter." Unfortunately, we still don't know which White House offices or officials pressured EPA. Burnett repeatedly refused to answer the committee's questions on who communicated with EPA or what exactly was discussed. Burnett informed the committee he was under instruction from senior EPA officials to keep that information under wraps. Check out the Committee's investigation and supporting documents here.