The Senate confirmed David Bernhardt as second in charge at the Interior Department on Monday despite recent claims that he continued to represent a client as a lobbyist after his registration was deactivated.

Bernhardt’s confirmation passed by a 53-to-43 vote largely along party lines. Republicans praised Bernhardt, who previously worked as a solicitor at Interior, as an experienced complement to Secretary Ryan Zinke. Democrats called him a “walking conflict of interest” for representing corporate interests opposed to regulations at the department that aim to help clean air and water.

Sen. Lisa Murkowski (R-Alaska) called his selection “an excellent choice” because of “his extensive experience and knowledge of issues that are important to Alaskans and western states.” But his work for a client out west, Westlands Water, prompted a nonprofit group to ask the Justice Department to investigate whether he violated the Lobbying Disclosure Act.

Bernhardt’s registration as a lobbyist was deactivated in November, but the group, Campaign for Accountability, claimed to have evidence showing that he worked on the water agency’s behalf in the offices of his employer, the Brownstein, Hyatt, Farber and Schreck law firm,which represents big farms and oil companies. There was no indication as to whether he was paid for the work, but the director of the campaign said under the rules that doesn’t matter.

“This administration has already established a dangerous pattern of putting special interests above the interests of the American people and the health of our public lands,” said Drew McConville, a senior governmental affairs director for the Wilderness Society. “Americans across the country are watching closely, and we are calling on Members of Congress to hold newly-confirmed Deputy Secretary Bernhardt accountable for his actions going forward and insist that our public lands be protected for future generations.”