A federal judge in Washington has ruled against Donald Trump in a financial records dispute with Congress.

US District Judge Amit Mehta, who was appointed by Barack Obama, said the president cannot block a House subpoena of financial records.

He said the Democratic-led House committee seeking the information has said it believes the documents would help legislators consider strengthening ethics and disclosure laws, among other things.

The committee’s reasons were “valid legislative purposes”, Judge Mehta said, and it was not for him “to question whether the committee’s actions are truly motivated by political considerations”.

The decision comes amid a widespread effort by the White House and the president’s lawyers to refuse to co-operate with congressional requests for information and records.

In the case before Judge Mehta, Mr Trump and his business organisation sued to block the subpoena issued in April to Mazars USA, an accountant for the president and Trump Organisation.

Mr Trump’s lawyers accused Democrats of harassing the president and said the subpoena “has no legitimate legislative purpose”.

Mr Trump’s lawyers, in suing in both Washington and New York in an attempt to beat back congressional subpoenas, said congressional investigations are legitimate only if there is legislation that might result from them.

In the New York case, Mr Trump, his business and family have sued Deutsche Bank and Capital One to prevent the financial companies from complying with subpoenas from the House Financial Services Committee and the House Intelligence Committee for banking and financial records.

A Wednesday hearing is planned in that case.

Even before the ruling, scholars had said Mr Trump’s legal argument had little merit and that Congress has broad powers to investigate.