• Rudy Giuliani has had his New York law license revoked, while his Washington, D.C., license remains under review.
• A New York appeals court disbarred Giuliani because of his alleged involvement in helping Donald Trump overturn the results of the 2020 election.
• Giuliani is facing a slew of legal battles, which forced him to file for bankruptcy protection in December.

Rudy Giuliani's New York law license was revoked on Tuesday amid allegations that he assisted former President Donald Trump's failed effort to overturn the results of the 2020 election.

Giuliani's law license remains under review in Washington, D.C.

"The disciplinary charges stem from the allegations that respondent communicated demonstrably false and misleading statements to courts, lawmakers, and the public at large in his capacity as lawyer for former President Donald J. Trump and the Trump campaign in connection with Trump's failed effort at reelection in 2020," attorneys for the New York appeals court that issued the ruling wrote in their decision.

Giuliani was first admitted to practice law in New York in June 1969.

"Mr. Giuliani is obviously disappointed in the decision. We are weighing our appellate options," Giuliani's lawyer Barry Kamins said in a statement to NBC News.

The New York appeals court cited a variety of false statements Giuliani has made to allegedly help Trump convince courts to invalidate the results of the 2020 election.

Among the examples the court laid out in the filing include Giuliani claiming that there was "endemic election fraud" in Philadelphia; that ballots had been smuggled from Long Island, New York; that thousands of non-U.S. citizens had voted in Arizona; and that Dominion Voting Systems machines had been manipulated in Georgia.

The former New York City mayor has been embroiled in legal battles over many of these statements.

In May, the former Trump lawyer was served criminal indictment papers at his birthday party on charges related to a failed conspiracy to overturn the 2020 election in Arizona.

In December, Giuliani was ordered to pay two Georgia election workers $148 million for defamation. Giuliani falsely claimed that the election workers committed ballot fraud, one of the misleading statements he made to allegedly assist in Trump's failed effort to invalidate the 2020 election results.

Soon after that verdict, Giuliani filed for bankruptcy protection.

— CNBC's Kevin Breuninger contributed to this report.