Former Bishop Heather Cook will be jailed for 10 years after she pleaded guilty to the manslaughter of a cyclist last year.

Prosecutors yesterday agreed a sentence of 20 years' jail time, but with with ten years suspended and five years' probation.

Cook, 58, hit and killed cyclist Tom Palermo, 41, when she drove her SUV into a bicycle lane in Baltimore on 27 December last year.

Having initially fled the scene, she later returned after prompting by friends.

Yesterday she pleaded guilty to three charges: automobile manslaughter, leaving the scene of a fatal accident, and driving while under the influence and texting while driving.

She was almost three times over Maryland's legal blood-alcohol limit, at 0.22 per cent.

Cook entered her pleas the day before her trial was scheduled to take place.

Formerly the first female Bishop in the Episcopal Diocese of Maryland, Cook resigned from the post on May 1 and is no longer a clergywoman.

One minister in the diocese described the situation as an "epic failure" on the part of the Episcopal Church.

Diocesan officials knew Cook had been convicted of driving under the influence of alcohol in 2010, but this information had not been formally disclosed to the people who elected her last year.

Following a diocesan meeting Rev Anjel Scarborough wrote in an open letter to her congregation at Grace Episcopal Church in Brunswick in January.

She said although the committee that appointed Cook appear to have followed the Church's national guidelines, "our guidelines are woefully inadequate and naïve in addressing the complex problems of substance abuse and addiction."

Scarborough lists a summary of the many failures she perceives in this tragic event.

"In the end, this was an epic failure. It was the failure of a process to stop a candidate for bishop from being put forward when clearly her alcoholism was not in remission. It was a failure of Heather's to choose not to treat her alcoholism and conceal her past. This resulted in the death of a husband and father – something which Heather will have to live with for the rest of her life and for which she may be incarcerated. This was our failure of Heather too.

"As the Church, we set her up to fail by confusing forgiveness with accountability. We did not hold her accountable to a program of sobriety and we failed to ask the tough love questions which needed to be asked. In so doing, we offered cheap grace – and that is enabling."