President Donald Trump has been invited to the Congress’ first impeachment hearing on December 4.

Democratic chairman of the House Judiciary Committee Jerrold Nadler said President Trump could either attend or “stop complaining about the process”.

If the president does attend, he would be able to question witnesses.

The hearing would mark the next stage in the impeachment inquiry, which centers on a July phone call between PresidentTrump and Ukrainian President Volodymyr Zelensky.

In that call, President Trump asked Volodymyr Zelensky to investigate Joe Biden, currently the front-runner to be the Democratic candidate in next year’s presidential election, and his son Hunter Biden, who had previously worked for Ukrainian energy company Burisma.

The probe is looking into whether President Trump used the threat of withholding US military aid to pressure Ukraine into investigating the Bidens. Donald Trump has denied any wrongdoing and has called the inquiry a “witch hunt”.

Last week, the House Intelligence Committee wrapped up two weeks of public hearings, which followed several weeks of closed-door witness interviews.

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Democratic chairman of the Intelligence Committee Adam Schiff said the committees leading the probe – Intelligence, Oversight and Foreign Affairs – are now working on their report, which will be issued on December 3.

On November 26, the latest transcript of inquiry evidence was released, detailing testimony by senior budget official Mark Sandy.

Mark Sandy told the House investigators that two White House budget officials had resigned following the withholding of military aid to Ukraine. He said that one, a lawyer, had expressed concern that the action could be a violation of a 1974 budget law.

Jerrold Nadler said in a statement that he had written to President Trump inviting him to the hearing next month.

He said: “At base, the president has a choice to make.

“He can take this opportunity to be represented in the impeachment hearings, or he can stop complaining about the process.

“I hope that he chooses to participate in the inquiry, directly or through counsel, as other presidents have done before him.”

In his letter to the president, Jerrold Nadler said the hearing would be an opportunity to discuss the historical and constitutional basis for impeachment.

He has given President Trump until 18:00 EST on December 1 to confirm whether or not he will be at the hearing, and if so, to let the committee know who his counsel will be.

The Judiciary Committee is expected to begin drafting articles of impeachment – which are the charges of wrongdoing against the president – in early December.

After a vote in the Democratic-controlled House, a trial would be held in the Republican-run Senate.

If Donald Trump was convicted by a two-thirds majority – an outcome deemed highly unlikely – he would become the first US president to be removed from office through impeachment.