Facing a Washington DC legal ethics prosecution over his role in Donald Trump’s attempt to overturn the 2020 election, the former New York mayor Rudy Giuliani has turned to a cast of characters from that failed effort.

A witness list filed by lawyers for Giuliani on Friday included Doug Mastriano, the Republican candidate for governor in Pennsylvania; the former Trump campaign lawyer Jenna Ellis; and Christina Bobb, an attorney currently caught up in Trump’s fight with the US Department of Justice over the retention of classified records.

Also among those named were the former Florida attorney general Pam Bondi; Peter Navarro, a former Trump trade adviser charged with contempt of Congress in the January 6 investigation; former Trump campaign manager Corey Lewandowski; and Bernard Kerik, a former New York police commissioner who Trump pardoned of felonies that sent him to jail.

Phil Waldron, a former army colonel turned Texas bar owner who pushed baseless electoral fraud claims, was also on the witness list.

Giuliani is accused of mounting a frivolous election challenge in Pennsylvania – one of four states, with Arizona, Georgia and Michigan, on which the attempt to overturn Joe Biden’s presidential election victory focused and which Trump this week named in an intemperate response to a subpoena from the House January 6 committee.

The DC office of disciplinary counsel intends to call Giuliani as a witness. The former mayor appears on his own list too.

Giuliani has said he had a “good faith basis” for contesting mail-in ballots in Pennsylvania.

But his work as Trump’s personal attorney – for which he has famously struggled to secure payment – landed him in legal jeopardy on a number of fronts.

Giuliani’s role in approaches to Ukraine for political dirt on Trump opponents including Biden landed him in the middle of Trump’s first impeachment.

Trump’s second impeachment, for inciting the Capitol riot on 6 January 2021, was the result of the failure of legal attempts to overturn the 2020 election.

In Georgia, Giuliani has been named as the target of a criminal investigation into efforts to overturn the election result there.

In New York, he has been sued by Dominion Voting Systems, a maker of election machinery.

Giuliani is also suspended from practicing law in New York state.

Writing for Slate, the Harvard law professor Laurence H Tribe and Dennis Aftergut, a former federal prosecutor, said Giuliani and the law professor John Eastman were “the two chief ‘generals’ [who] orchestrat[ed] Trump’s abuse of the law to overturn the election”.

The authors added: “In joining the bar, lawyers take an oath to support the US constitution much like the one that Article VI of the constitution requires of all public officials. Lawyers who betrayed that oath in ways that led to the deadly insurrection of January 6 are no better than a physician who violates the Hippocratic Oath to ‘do no harm’.”

The complaint in the DC case says Giuliani violated two Pennsylvania rules that bar attorneys from bringing frivolous proceedings without a basis in law or fact and prohibit conduct prejudicial to the administration of justice. The charges can lead to the suspension of a license to practice or disbarment.

The hearing is set for December.