A Democratic member of the U.S. Surface Transportation Board, who was dismissed by President Donald Trump before a crucial rail merger evaluation, has initiated a lawsuit, alleging his removal was unlawful.

Robert Primus, a board member since 2001, claims he was not informed of the reasons for his dismissal on August 28, which endangers the independence of the five-member STB. His removal occurred just before the board was set to review Union Pacific’s proposed $85 billion acquisition of Norfolk Southern, aiming to create a pioneering transcontinental railroad.

Primus expressed concerns, emphasizing the necessity for an independent and transparent board as per Congress’s 138-year-old mandate. He warned that failing to ensure this could destabilize the supply chain and disrupt the economic network, affecting railroads, shippers, and workers alike.

The White House has yet to comment on the lawsuit filed on Tuesday, as its press office is understaffed due to the ongoing government shutdown. At the time of the firing, the only public statement cited was Primus’s purported misalignment with the President’s “America First” agenda.

Nevertheless, Primus’s supporters, including Skye Perryman, CEO of Democracy Forward, argue that this action disregards the founding principles of the STB. According to Congress, board members should only be terminated for inefficiency, neglect of duty, or malfeasance.

Perryman criticized the President’s decision, stating that Trump unlawfully targets members of independent boards, defying the legal framework that requires the Surface Transportation Board to remain impartial and free from political influence.

Trump has fired a string of board members at various agencies that are supposed to be independent including the Federal Reserve, the National Transportation Safety Board, Equal Employment Opportunity Commission and Nuclear Regulatory Commission.

Primus said he always strove to be impartial and apolitical in his time on the board that was supposed to continue through the end of 2027. His firing broke a 2-2 tie between Republicans and Democrats on the board and cleared the way for Trump to appoint two more members.

Every rail worker union, the nonprofit Rail Passengers Association and Democratic members of Congress quickly condemned the firing when it happened. Democratic Sen. Tammy Baldwin said at the time Primus was fired that it looked like Trump was trying to stack the board so it will rubberstamp the Union Pacific merger.

Since then, Trump has said the merger sounds good to him after he met with Union Pacific’s CEO in the Oval Office last month.

Primus was the only board member to oppose Canadian Pacific’s acquisition of Kansas City Southern railroad when it was approved two years ago because he was concerned it would hurt competition, which remains a concern for him though he hasn’t taken a position on the UP-NS deal. He was named board chairman last year by former President Joe Biden and led the board until Trump, after his election, elevated Republican Board member Patrick Fuchs to chairman.