Two environmental groups sued the EPA Tuesday in federal court for its policy banning scientists who receive agency funding from serving on advisory boards.

EPA Administrator Scott Pruitt in October announced a directive to block scientists who receive EPA funding from serving on the EPA’s 22 advisory committees, including three major ones: the Science Advisory Board, Clean Air Scientific Advisory Committee, and Board of Scientific Counselors.

Under the policy, people receiving EPA grants serving on the boards had to choose whether to keep the grant or continue their work on the boards. Most board members serve three-year terms.

“Under the guise of improving advisory board balance, Pruitt is using this directive to populate advisory boards with industry-funded scientists and state government officials who have made a career fighting federal regulations,” said the Union of Concerned Scientists and Protect Democracy, in announcing the lawsuit.

The groups claim the Science Advisory Board, for example, now includes 14 new members who consult or work for the chemical or fossil fuel industries.

In the suit, filed in the U.S. District Court for the District of Massachusetts, the groups say Pruitt’s directive is arbitrary and capricious and is not supported by law or EPA precedent.

The complaint also says the EPA’s policy violates the Federal Advisory Committee Act, which requires all advisory committees to be “fairly balanced” and not be “inappropriately influenced” by the appointing authority.

Critics say Pruitt’s policy enabled him to fill EPA’s boards with corporate interests who support his deregulatory agenda.

But Pruitt has said the new members represent a broader geographic area than in previous boards. He said his goal is to provide more “fulsome” representation on the boards, with more members who are state regulators and energy industry representatives.

He insists all nominees will continue to go through an ethics process to ensure that they are not in conflict with rules they advise on.

Republicans long complained that the Obama administration favored filling EPA's advisory boards with scientists who backed its policies on climate change.

House Republicans have unsuccessfully pursued legislation in recent years that would prevent recipients of agency grants from serving on EPA's boards.