Maryland bishop Heather Cook, who is facing manslaughter charges for the hit-and-run of a cyclist in December, has been asked to resign by her diocese.

In a letter to Cook dated January 26, members of the Standing Committee of the Episcopal Diocese of Maryland say they "agreed unanimously that you are no longer able to function effectively in the position of Bishop Suffragan given recent events.

"Therefore, we respectfully call for your immediate resignation...The Standing Committee arrived at this decision after significant and prayerful discernment, and with due and proper consideration for the best interests of the diocese and its people.

"We continue to hold you in our prayers."

Cook has made no statement since the incident, and her lawyer, David Irwin, yesterday declined to comment on the resignation request.

Cook hit 41-year-old cyclist Tom Palermo after driving her SUV into a bicycle lane in Baltimore on 27 December last year. She then left the scene of the accident, but returned around 20 minutes later. Palermo died of head injuries sustained in the incident shortly after.

Testing showed that the bishop was three times over the alcohol limit for drivers in Maryland at the time of the incident, and she later confessed in court that she has an alcohol problem. She has been charged with driving under the influence of alcohol and causing an accident due to texting while driving among other offences, and faces up to 20 years in prison if convicted.

Cook's preliminary hearing is scheduled for February 6, and the bishop last week checked into an alcohol treatment facility after posting $2.5million bail.

The Episcopal Bishop of Maryland has said the diocese is in "deep pain" as a result of her actions.

Eugene Taylor Sutton, Cook's senior, wrote in a pastoral letter earlier this month: "The Diocese of Maryland is in deep pain. Words barely express the depth of our shock and despair over the events and revelations of the past two weeks.

"There are still too many questions for which there are no easy answers, and we are filled with anger, bitterness, pain and tears. Our thoughts and prayers remain with the Palermo family in their bereavement and for ourselves as a diocese in mourning."