The House Oversight Committee is expanding its probe of the Obama administration’s rules limiting greenhouse gas emissions from cars and light trucks, according to a letter it sent to the head of the Environmental Protection Agency.

The investigation led by committee chairman Darrell Issa (R-Calif.) reflects the ongoing battle between House leaders and the administration over the extent to which EPA can address climate change without congressional input.

In the 13-page letter committee sent Friday to EPA administrator Lisa P. Jackson, Issa suggested that by pressing ahead with regulations to curb greenhouse gas emissions from vehicles, Jackson “set in motion a series of events which have led inexorably to the expansion of power exercised by EPA. Not only has this expansion occurred without the express consent of Congress, but it also appears that EPA has successfully avoided scrutiny of its actions by the Judicial branch of government as well.”

The White House has brokered two sets of agreements between automakers and state and federal regulators on fuel economy over the past 21 / 2 years that cut greenhouse gas emissions, both of which have come under fire from Issa and some other congressional Republicans as federal overreach.

In May 2009 the parties — which included California officials, who had enacted their own limits several years before — agreed that by model year 2016 cars and light trucks must average 35.5 miles per gallon. Then in late July, automakers and regulators reached a second agreement that would require U.S. vehicle fleets to average 54.5 miles per gallon or 163 grams per mile of carbon dioxide equivalent by 2025, a 50 percent cut in greenhouse gases compared with today’s vehicles.

Issa began investigating the rule-making on Aug. 11, demanding the White House provide greater disclosure on how it reached the two deals.

He asked that EPA turn over a broad range of documents relating to the two rule-makings, including “all documents and communications” related to the negotiation and development of the two greenhouse gas standards, a list of all the agency officials who participated in the rulemakings, and all technical assessment reports and studies the agency used as the basis for the tighter emission rules.

EPA spokeswoman Betsaida Alcantara wrote in an e-mail that in light of Issa’s request, the agency will respond “appropriately and we will continue to work with all our partners to continue to move forward on this historic clean cars initiative.”

In the letter, Issa notes that two of the nation’s major automakers — GM and Chrysler — might have felt obligated to reach a deal with the administration on greenhouse gas limits because the federal government had given them massive loans. He also questioned whether EPA complied with the Administrative Procedures Act (APA), because many of the discussions over how best to set the new limits were not subject to public scrutiny.

“The Administration’s apparent preference to cut back-room deals that exclude important stakeholder involvement is exactly the type of activity that the APA was designed to prevent,” Issa wrote.

Issa sent a separate letter Friday to Transportation Secretary Ray LaHood questioning whether the National Highway Traffic Safety Administration also acted outside its authority by helping craft the rules.

Jesse Prentice-Dunn, a transportation policy analyst for the advocacy group Sierra Club, described the inquiry as a political stunt.

“It seems that Rep. Issa is more interested in scoring political points than common sense policies that everyone — from automakers to environmentalists — support,” Prentice-Dunn said. “Improved vehicle standards will save Americans thousands of dollars at the pump, reduce our dependence on oil and renew the American auto industry’s role as a leader in the global economy.”