The politically charged effort comes following record-setting levels of illegal immigration last year. Voters cite immigration as a top concern ahead of the November 5 presidential and congressional elections.

The 100 senators are due on Wednesday to be sworn in as jurors for a trial that could take at least a week.

However, top Senate Democrat Chuck Schumer is expected to try to end it before it starts.

He and other Democrats argue that House Republicans are motivated by political concerns and have failed to demonstrate illegal actions on Mayorkas’ part.

“Every time there’s a policy disagreement in the House, they send it over here and tie the Senate in knots to do an impeachment trial? That’s absurd. That’s an abuse of the process. That is more chaos,” Schumer said in a speech earlier in the day.

Republicans impeach US homeland security chief over border crisis

Republicans were expected to use procedural hurdles to prevent Democrats from dismissing the case, or at least slow them down.

“Never before has the Senate agreed to a motion to table articles of impeachment. Not for an officer of either party. Not once,” Senate Republican Leader Mitch McConnell said in a Senate speech.

Earlier in the day, Mayorkas spent nearly three hours testifying to the House Homeland Security Committee – the panel that originated his impeachment. He was called to testify about his agency’s budget for next year, but impeachment permeated the hearing.

“I thank you for coming. I understand the emotions of being here today,” Republican Chairman Mark Green said in his closing statement.

Some lawmakers have argued that impeachment is a poor use of time as Congress confronts global worries, including the risk of the Israel-Gaza war possibly turning into a regional conflict and Russia gaining ground in its war against Ukraine.

Several Republicans have said removing Mayorkas from office would accomplish little, as Biden’s immigration policies would remain in force.

Mayorkas, a former federal prosecutor, denies the House charges, Biden is standing behind him, and even some Republicans have said they see no illegal activities to back up the allegations.

While many Republicans accuse Mayorkas of creating a “crisis” they say jeopardises national security due to record numbers of migrants arriving at the southern US border with Mexico, the House had been in no rush to actually deliver its impeachment papers to the Senate, despite having approved them more than two months ago.

US Republicans defeat Senate border deal

Biden’s election rival, Republican former president Donald Trump, has made immigration a key focus of his campaign and earlier this year helped torpedo a bipartisan Senate border bill that would have toughened enforcement.

On Friday, Trump put forth a legislative proposal trying to link conditions at the border to his long-standing false claim that his 2020 defeat to Biden was the result of fraud.

With some Senate Republicans fuming over Schumer’s anticipated move for a dismissal of the case without a trial, they have been staging procedural hurdles against even routine actions that keep the chamber operating efficiently.

Last Thursday, for only the seventh time in 35 years, they insisted on a time-consuming roll-call vote to merely allow the Senate to recess for a long weekend.

Mayorkas is only the second presidential cabinet official facing removal through impeachment. The last time was in 1876.