In March, a coalition of 17 state attorneys general announced they would begin an investigation aimed at corporate forces like ExxonMobil that have — over a period of decades — obstructed efforts to combat climate change. Now, corporations and their allies in Congress are striking back.

Thirteen Republicans on the U.S. House Science, Space, and Technology Committee circulated letters on Wednesday to the attorneys general and several environmental organizations. They claim the proceedings amount to a violation of free speech, and so they’re requesting documents related to the legal efforts against Exxon and industry-funded nonprofits.

The letters read, in part:

The Committee is concerned that these efforts to silence speech are based on political theater rather than legal or scientific arguments, and that they run counter to an attorney general’s duty to serve ‘as the guardian of the legal rights of the citizens’ and to ‘assert, protect, and defend the rights of the people.’ These legal actions may even amount to an abuse of prosecutorial discretion.

You read that right: The House Science Committee — the committee that’s headed by noted climate change denier Rep. Lamar Smith (R-Texas) and has jurisdiction over federal scientific research — wants everyone to stop picking on poor little Exxon and the most profitable industry in human history. As Greenpeace executive director Annie Leonard said, “America’s least-respected politicians have now courageously stepped up to defend one of America’s most-hated corporations from scrutiny.”

Exxon, proving itself perfectly capable of fighting its own battles, has more payback in the works: It filed court papers last month to challenge one attorney general’s investigation.