Senate Republicans are poised to use their majority to confirm President Donald Trump's nominee to lead the Environmental Protection Agency, despite calls from Democrats for a delay.

A vote on Scott Pruitt's nomination is set for Friday. As part of a public records lawsuit, a state judge in Oklahoma on Thursday ordered Pruitt to release thousands of emails that he exchanged with oil and gas executives by next week. Pruitt, who is Oklahoma's attorney general, has refused to release the emails for more than two years.

Democrats boycotted a committee vote on Pruitt's nomination last month, citing his refusal to hand over the emails, and on Thursday called on Senate Majority Leader Mitch McConnell, R-Ky., to delay Pruitt's confirmation vote until the nominee turns over the thousands of requested emails from his time as attorney general.

Republican leaders, however, have shown no signs they intend to wait for the documents to be released before voting to confirm him.

"Scott Pruitt is the most thoroughly vetted nominee we've ever had to lead this agency," said Sen. John Barrasso, R-Wyo., chairman of the Senate Environment and Public Works Committee. "These boycotts and these delay tactics do nothing to protect our environment or the health of Americans."

So far, Sen. Susan Collins of Maine is the lone Republican saying she will vote against Pruitt. Her no vote could be cancelled out by Democratic Sen. Joe Manchin of coal-dependent West Virginia, who is expected to cross party lines to support Trump's pick.

To dramatize their cause, Senate Democrats kept the Senate in session through the night with a series of speeches opposing his confirmation. Democrats were still marching to the floor at daybreak.

Pruitt's nomination was strongly opposed by environmental groups and hundreds of former EPA employees, who predict he will roll back the agency's environmental enforcement efforts. During his Senate confirmation hearing last month, Pruitt said he disagreed with Trump's past statements that global warming is a hoax. However, Pruitt has previously cast doubt on the extensive body of scientific evidence showing that the planet is warming and man-made carbon emissions are to blame.

The 48-year-old Republican is closely aligned in his home state with oil and gas companies, whose executives have backed his political campaigns. Though Pruitt ran unopposed for a second term in 2014, public campaign finance reports show he raised more than $700,000, much of it from people in the energy and utility industries.

The Center for Media and Democracy filed multiple public records requests for Pruitt's emails to coal, oil and gas corporations going back to 2015. It sued him last week.

In a hearing Thursday, Oklahoma District Court Judge Aletia Haynes Timmons concluded "there really is no reasonable explanation" for why Pruitt's office hasn't complied with the request for his emails. Timmons ordered Pruitt to turn over the records by Tuesday and to comply with other open records requests by the group in 2015 and 2016 within 10 days.

Pruitt's office says about 400 documents were turned over on Feb. 10, but Timmons says more than 3,000 have been withheld.

As attorney general, Pruitt filed 14 lawsuits challenging EPA regulations. He joined a multistate lawsuit opposing the Obama administration's plan to limit planet-warming carbon emissions from coal-fired power plants. Pruitt also sued over the EPA's recent expansion of water bodies regulated under the Clean Water Act. It has been opposed by industries that would be forced to clean up polluted wastewater.

Democrats pressed Pruitt during his confirmation hearing on whether he would recuse himself from those still-pending cases. Pruitt said he would review his involvement on a case-by-case basis and recuse himself if directed to do so by the EPA's ethics office.

— Tim Talley contributed to this report from Oklahoma City

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