U.S. Sen. Tom Carper sent a letter Monday asking EPA Inspector Standard Sean O’Donnell to grow the agency’s investigation into the new gasoline effectiveness guidelines adopted beneath the Trump administration.

In late February, Carper requested the inspector general to open up an investigation into “likely illegal efforts and procedural troubles” linked to the car emissions guidelines, citing stories acquired by his business office that EPA political officers were being dodging sure rule-producing and procedural necessities and appeared to be striving to conceal paperwork important of the draft guidelines.

President Donald Trump’s rollback of Obama-era car emissions standards was accomplished March 31. The new guidelines need 1.five % once-a-year will increase in effectiveness via 2026. The closing guidelines consider result June 29.

In the letter Monday, the Delaware congressman and top Democrat on the Senate Natural environment and Community Works Committee reported his business office has acquired new paperwork revealing “significant inaccuracies and technical errors in the closing rule” that EPA officials experienced requested the Division of Transportation to appropriate.

“These elements describe a essentially and legally flawed rule produced by what might be the most procedurally problematic process my business office has ever reviewed,” Carper wrote in the letter.

Carper is asking the inspector general to more investigate irrespective of whether EPA officials “improperly circumvented the Clear Air Act, regulatory and other procedural necessities throughout the administration’s preparation and assessment of the closing Safer Cost-effective Gasoline Economical Autos rule,” according to a news release from the committee.

“I ask for that you identify how so a lot of significant variations were being designed to the rule right after it was signed and ahead of it was published, and irrespective of whether the process followed to make this sort of variations was acceptable, transparent and precedented,” Carper reported.

Jeffrey Lagda, a spokesman for the EPA inspector general, reported in an email to Automotive Information that O’Donnell has acquired the letter.

“He and his management team are at present reviewing the letter and the facts presented,” Lagda reported.