WASHINGTON — Democrats and environmental groups are criticizing President Donald Trump’s nominee for the No. 2 position at the Interior Department, arguing that David Bernhardt has continued to advise a California water district even after he withdrew his formal registration as a lobbyist last year.

His nomination flies in the face of Trump’s pledge to “drain the swamp” in Washington of influence peddlers, said Sen. Maria Cantwell, D-Wash.

“I’m afraid he’s not draining the swamp. He’s actually helping to fill it,” Cantwell said.

The Senate is scheduled to vote Monday night on the nomination of Bernhardt, a lawyer and Interior official under President George W. Bush. If confirmed, as expected in the Republican-led Senate, Bernhardt would serve as the top deputy to Interior Secretary Ryan Zinke.

The League of Conservation Voters and other environmental and watchdog groups have urged senators to oppose Bernhardt’s nomination, saying he has long lobbied for the oil and gas industry, mining companies and other businesses regulated by Interior.

“Bernhardt’s list of conflicts of interest is extensive and should disqualify him from this position,” 150 groups said in a letter to senators in May.

Spokeswoman Heather Swift said Zinke was “excited to have David Bernhardt, a highly qualified, veteran official, return to the department to help advance ‘America First’ policy priorities” set by Trump.

“Strongly worded press releases issued by special interest groups alleging any wrongdoing are patently false and are desperate attempts to stop the progress that is being made at the department on behalf of the American people,” Swift said.

Cantwell and other critics said they were concerned over media reports that Bernhardt was working for the Westlands Water District, the nation’s largest irrigation district, at the same time he was serving on the Trump transition team. Bernhardt’s law firm represented Westlands in four lawsuits against Interior.

At a confirmation hearing in May, Bernhardt told Cantwell he would recuse himself from matters involving Westlands and other clients for at least a year, unless he receives authorization to do so.

“If I get a whiff of something coming my way that involves a client or former client for my firm, I’m going to … run straight to the ethics office,” Bernhardt said.

Cantwell was unimpressed.

“I remain concerned about his record on behalf of these corporations at the expense of the environment, his tenure at the Department of the Interior and many other challenges,” she said on the Senate floor last week.

Sen. Bill Nelson, D-Fla., said he will oppose Bernhardt because of his refusal to support a moratorium on oil drilling off the Florida coast in the Eastern Gulf of Mexico.

“When it comes to the eastern Gulf, there is no good way to increase offshore production while balancing environmental concerns,” Nelson said, noting that the 2010 BP oil spill fouled the gulf region for years and continues to cause problems.

Nelson helped pass a congressional ban on oil drilling 125 miles off Florida’s coast more than a decade ago. The ban is set to expire in 2022 and a number of congressional Republicans and industry groups are in favor of ending it.

Trump signed an executive order in April to expand oil drilling in the Arctic and Atlantic oceans, reversing restrictions imposed by President Barack Obama. Zinke also has ordered a review of a five-year offshore drilling plan to boost production.

Sen. Cory Gardner, R-Colo., urged support for Bernhardt, a Colorado native who served as solicitor, Interior’s chief legal officer, during the Bush administration.

Bernhardt, a longtime friend, “is a strong voice for the West and extremely well-qualified to be deputy secretary,” Gardner said.

In this March 29, 2017 file photo, Interior Secretary Ryan Zinke speaks at the Interior Department in Washington. The Senate is on track to confirm President Donald Trump’s nominee for the No. 2 job at the Interior department over Democratic objections. David Bernhardt is a former lobbyist who once sued the department, hardly a fit with Trump’s call to drain the swamp. (AP Photo/Molly Riley)