The U.S. Senate on Tuesday confirmed President Donald Trump's former personal lawyer Emil Bove as a federal judge, installing a Trump loyalist who presided over a tumultuous period at the Justice Department on a crucial appeals court.

The Republican-majority Senate voted 50-49 to confirm Bove, who has been serving as a senior Justice Department official, to a lifetime appointment on the Philadelphia-based 3rd U.S. Circuit Court of Appeals.

Moderate Republican senators Lisa Murkowski of Alaska and Susan Collins of Maine joined all Democrats in opposition.

Bove overcame fierce opposition from Democrats, who walked out in protest when the Senate Judiciary Committee advanced his nomination, and more than 900 former Justice Department employees, who accused Bove of undermining the integrity of the department.

"This is a dark, dark day, a dark vote and a dangerous nominee Republicans have confirmed," Sen. Chuck Schumer, the top Senate Democrat, said following the vote.

Bove won support from Republicans who praised his experience as a federal terrorism prosecutor in New York and a defence lawyer for Trump in three criminal cases the president faced while out of office.

"I believe he will be diligent, capable and fair jurist," Republican Sen. Chuck Grassley, the chair of the Senate Judiciary Committee, said on Tuesday, decrying "vicious rhetoric and unfair accusations" levelled by Democrats.

Whistleblower complaints

Bove's confirmation will restore a majority for Republican appointees on the appeals court, which hears cases from New Jersey, Delaware and Pennsylvania.

Bove was at the centre of several confrontations with career officials as the Trump administration moved aggressively to align the department with its priorities.

A former Justice Department lawyer, Erez Reuveni, accused Bove in a whistleblower complaint of telling subordinates, in profane terms, during a March meeting that the government may defy courts if judges blocked the Trump administration from using emergency powers to deport migrants.

Bove told a Senate panel that he does not recall making such a remark and denied advising defiance of court orders.

Allegations against Bove from two other unnamed Justice Department whistleblowers have surfaced in recent days, according to lawmakers and public statements from lawyers and advocacy groups representing the whistleblowers.

Bove also ordered prosecutors to drop a corruption case against New York Mayor Eric Adams, a Democrat who cultivated ties with Trump, citing the mayor's upcoming re-election campaign and his assistance in Trump's immigration crackdown.

The directive prompted the resignations of 11 prosecutors, including the acting U.S. attorney in Manhattan, who accused Bove of relying on improper political considerations and striking a quid pro quo with Adams.

Bove has argued that dismissing the case was appropriate and denied any deal.

The Republican-led Senate has begun confirming Trump's first batch of judicial picks from his second term, seeking to build on the 234 judicial appointments from his first term that shifted the ideological makeup of the federal judiciary to the right.

Judges have issued scores of rulings halting or blocking Trump policies deemed unlawful, prompting Trump administration officials to accuse courts of exceeding their authority and thwarting the will of voters.