House Judiciary Committee Chairman Jerry Nadler said Wednesday morning that Democrats are ready for Senate Republicans to call former Vice President Joe Biden's son Hunter as an impeachment witness.

'We are prepared,' Nadler told reporters, after House Speaker Nancy Pelosi scooted away from the podium, asking one of her just-named impeachment managers to answer the question instead. 'In any trial, you call witnesses who have information about the allegations, about the charges.'

The New York Democrat reminded reporters that Trump is accused of holding up $400 million in military aid to Ukraine to pressure the country's president to announce an investigation into a 'domestic political opponent,' meaning 2020 hopeful Joe Biden.

'Any witness who has information about whether that is true or not true is a relevant witness,' Nadler said. 'Anybody – like Hunter Biden – who has no information about any of that, is not a relevant witness.'

'Any trial judge in this country would rule such a witness as irrelevant and inadmissible,' Nadler added, a comment that could mean Democrats will ask Chief Justice John Roberts to rule out the younger Biden as a witness.

House Judiciary Committee Chairman Jerry Nadler (center) answered a question about whether Democrats were prepared to have former Vice President Joe Biden's son Hunter testify as part of President Trump's impeachment trial in the Senate

Hunter Biden has become a central character in Trump's impeachment, having served on a board of a Ukrainian energy company. The president is accused of holding up military aid to pressure Ukraine's president to announce an investigation into this arrangement

Sen. Rand Paul, a Kentucky Republican, threatened to call Hunter Biden as an impeachment witness during a Monday evening tweet

Nadler also offered an analogy to make his point.

'If someone is accused of robbing a bank, witnesses who say "We saw him run into the bank, we saw him some place else," are relevant,' he said. 'A witness who says, "He committed forgery on some other document" is not relevant to the bank robbery charge. That’s the distinction.'

Hunter Biden became a central character in Trump's impeachment because he served on the board of the Ukrainian energy company Burisma.

This arrangement had the president and his allies claiming corruption, suggesting Hunter Biden had no experience in the sector, except having a vice president father.

President Trump has continued this line of attack, even since being impeached in the House of Representatives on December 18. And his Republican allies have maintained that Hunter Biden should testify during the president's Senate trial.

Sen. Rand Paul, a Kentucky Republican who's not always a consistent vote, taunted Democrats on Twitter Monday night saying he would call Hunter Biden as a witness.

'My colleagues can't have it both ways. Calling for some, while blocking others,' Paul said in the tweet. 'If we are going to give a platform to witnesses the Dems demand, I look forward to forcing votes to call Hunter Biden and many more!'

House Speaker Nancy Pelosi justified holding on to the two articles of impeachment for weeks by saying she wanted Senate leadership to extend her the 'courtesy' and reveal what the 'process would be.'

Democrats want to expand on the case the House made during the Senate trial, while Trump's allies would like the trial to be short-and-sweet.

It's due to start Tuesday, McConnell said this week.

The former vice president, on the Democratic debate stage Tuesday night, spoke of how Republicans have dragged he and his son through the mud for months as impeachment was front-and-center.

'This Republican Party, they've gone after - savaged my surviving son - gone after me, told lies that your networks and others won't even carry on television because they're flat-out lies,' Biden said.

'And I did my job, the question is whether he did his job. And he hasn't done his job,' the ex-veep said of Trump.