Bill Cosby’s lawyers are demanding a Pennsylvania judge step down from his upcoming molestation re-trial, alleging the jurist is biased because his wife works with sexual assault victims.

It appeared the latest move to hinder the April sexual assault trial by a legal team now headed by Tom Mesereau, the celebrity Los Angeles attorney who got Michael Jackson acquitted of child molestation in 2005.

“Mr Cosby respectfully requests that the court recuse itself from these proceedings to avoid the appearance of a conflict of interest and that the matter be reassigned,” read the memorandum, sent to AFP by the comedian’s spokesman.

The petition said there was “a clear appearance of partiality” as a result of the marriage between Judge Steven O’Neill and his wife Deborah, who is a social worker at the University of Pennsylvania’s office of counselling and psychological services.

His wife coordinates a sexual trauma outreach and prevention team and wrote her dissertation on acquaintance rape. The defence said she had also apparently donated money to an activist group that had specifically targeted Cosby.

The motion was filed in Norristown, Pennsylvania after O’Neill ruled last week that five additional women who claim to have been sexually assaulted by Cosby can testify.

At the first trial, which collapsed when the jury failed to reach a unanimous verdict, O’Neill ruled that only one other accuser could take the stand.

Jury selection is set to begin on April 2, following pre-trial motions on March 29 and 30. There was no immediate response from either O’Neill to the latest petition.

The June 2017 trial irrevocably damaged the once towering icon of US popular culture, loved by millions as “America’s Dad” and best known for his seminal role as a father and obstetrician on hit 1984-92 TV series “The Cosby Show.”

The 80-year-old is accused of drugging and molesting a former university basketball official at his Philadelphia home in 2004. He says their relations were consensual.