White House has sent letter to Democratic lawmakers saying President Trump and his lawyers will not participate in impeachment hearing sessions due to lack of ‘fundamental fairness.’

“We cannot fairly be expected to participate in a hearing while the witnesses are yet to be named and while it remains unclear whether the Judiciary Committee will afford the President a fair process through additional hearings,” White House counsel Pat Cipollone wrote to Jerrold Nadler, a Democrat from New York's 10th congressional district and Chairman of the House of Representatives Judiciary Committee.

Cipollone did not rule out participation in further proceedings, but he signaled that Democrats would first have to make major procedural concessions.

The Democratic-led House Judiciary Committee, tasked with considering charges known as articles of impeachment, had given Trump until Sunday night to say whether he would dispatch a lawyer to take part in the judiciary panel’s proceedings on Wednesday.

Trump’s aides have responded defiantly to the first of two crucial deadlines he faces in Congress.

Nadler has given the White House a Friday deadline to say whether Trump will mount a defense in broader impeachment proceedings. Nadler also set a second deadline of 5 p.m. (2200 GMT) on Friday for Trump to say whether he or his legal counsel would participate in further proceedings expected next week to examine evidence against him.

House Democrats launched an impeachment inquiry against Trump in September after a whistleblower alleged the Republican president pressured Ukrainian President Volodymyr Zelensky to investigate former Vice President Joe Biden and his son Hunter, who had served as a director for Ukrainian energy company Burisma.

The impeachment probe shifted to a public phase on November 13 after weeks of closed-door interviews in the House.

An overwhelming 70 percent of US adults think Trump’s action towards Ukraine was wrong, and a slim majority of Americans, 51 percent, believe Trump’s actions were both wrong and he should be removed from office, according to an ABC News/Ipsos poll released on November 19.

Three investigating panels, led by the House Intelligence Committee, are due to release a formal report this week when lawmakers return on Tuesday from a Thanksgiving recess. The report will outline evidence gathered by the Intelligence, Foreign Affairs and Oversight committees.

Members of the intelligence panel will review the report in a classified setting on Monday evening, and the full committee will consider and vote on it on Tuesday before forwarding it to the Judiciary Committee, according to an Intelligence Committee official and a person familiar with the matter.

Trump has denied any wrongdoing, calling the impeachment inquiry a "witch hunt."