WASHINGTON (Reuters) - The Senate on Thursday moved closer to approving President Donald Trump’s pick to head the Environmental Protection Agency even as nearly 800 former officials urged the chamber to reject the nominee, who sued the agency more than a dozen times as attorney general of oil-producing Oklahoma.

FILE PHOTO: Oklahoma Attorney General Scott Pruitt testifies before a Senate Environment and Public Works Committee confirmation hearing on his nomination to be administrator of the Environmental Protection Agency in Washington, U.S., January 18, 2017. REUTERS/Joshua Roberts/File Photo

The 773 former officials signed a letter sent to the Senate that said Pruitt’s record and public statements suggest he does not agree with the underlying principles of U.S. environmental laws. Pruitt has also cast doubts on the science of climate change.

“Mr. Pruitt has shown no interest in enforcing those laws, a critically important function for EPA,” the letter said.

A spokesman for Pruitt did not immediate respond to a request for comment.

The Senate advanced Pruitt’s nomination on Thursday, clearing the way for a final vote, expected on Friday.

Republican Senator Susan Collins came out against Pruitt on Wednesday, saying she had doubts about whether he would fully support the EPA’s mission to protect human health and the environment.

But Pruitt only needs a simple majority for approval, so unless Collins is joined by more Republicans, who control the Senate 52 to 48, his nomination is likely to succeed.

Making Pruitt’s chances even likelier, Senator Heidi Heitkamp, a Democrat, said she would cast her for vote for him, even though she had “concerns” about his commitment to renewable power and to cut emissions blamed for climate change.

Joseph Santarella, an EPA enforcement lawyer under former Republican and Democratic administrations, who signed the letter protesting Pruitt, said his lawsuits against the agency demonstrated he had “a fundamental lack of understanding and respect for the vital role that EPA plays in ensuring clean air and water for every American.”

Senator John Barrasso, a Republican from coal-producing Wyoming and head of the Senate energy committee, said Pruitt had “led the charge to rein in big government and Washington overreach.”

The public could soon learn more about Pruitt’s communications with energy companies while he was suing the EPA.

Oklahoma County District Court Judge Aletia Timmons ruled that Pruitt will have to turn over 3,000 emails between his office and energy companies to her by Tuesday. Timmons will review the emails before deciding which of them to release.

A watchdog group, the Center for Media and Democracy, has sought the release of the documents since January 2015.