Former President Donald J. Trump plans to fight the release of his tax returns to Congress, a lawyer for Mr. Trump said on Monday.
The comments from the lawyer, Ronald P. Fischetti, came days after a legal opinion was issued by the Justice Department that said that the Treasury Department must turn over six years of the former president’s tax returns to congressional investigators.
Mr. Fischetti on Monday called the opinion “absolutely ridiculous” and said that he expected the legal battle over the release of the returns to go on for months.
“We’re going to fight this tooth and nail,” he said.
The opinion, which the Treasury said that it would comply with, opened the possibility that the returns, which Mr. Trump has fought for years to keep secret, could be released to Congress. But even if the returns are handed over to Congress, Mr. Trump’s tax information may not become public immediately or at all.
In 2019, the Treasury Department asked the Department of Justice for guidance on whether it was allowed to comply with a request for the returns from the House Ways and Means Committee. Lawyers at the Justice Department found then that the Treasury was justified in not turning over the returns.
Mr. Fischetti argued Monday that the Justice Department had reversed that position without any new information having come to light.
Judge Trevor McFadden, of the U.S. District Court for the District of Columbia, who is overseeing the dispute, asked lawyers for the House committee and for Mr. Trump to appear before him on Wednesday, when he is expected to lay out a timeline for written arguments.