Donald Trump and his businesses sued the Democratic chairman of the House Oversight committee on Monday to block a subpoena requesting the president's financial records.

It is the latest move in a fierce tussle between the White House and Democrats in Congress amid allegations about the president's finances.

In a court filing in Washington, the president's lawyers argued congressman Elijah Cummings "has no legislative purpose" to issue the subpoena and accused Democrats of using their majority in Congress to harass him.

“The Democratic Party, with its newfound control of the US House of Representatives, has declared all-out political war against President Donald J Trump," the lawsuit stated. “Subpoenas are their weapon of choice.”

The lawsuit asked the court to block a subpoena issued to Mr Trump’s accounting firm, Mazars, last week demanding several years of the president's financial statements.

The lawsuit, which will be fiercely contested in court, follows a string of moves in recent weeks by Mr Trump and his businesses to block the Democrats from getting their hands on his financial records.