The last remaining bishop mentioned in a damning report on the failure of the Catholic Church in Ireland to deal with allegations of child abuse is facing calls to step down.

The Bishop of Galway Dr Martin Drennan was one of five bishops mentioned in the Murphy report, which lifted the lid on decades of unreported child abuse within the Archdiocese of Dublin.

He is the only bishop mentioned in the report not to have stepped down. Diocesan communications manager Fr Seán McHugh told The Irish Times the bishop was “strong in his belief that he did nothing wrong”.

The chief executive of victim support group One in Four Maeve Lewis said Dr Drennan should do the “honourable thing” and resign.

“How many children were abused in Dublin between 1997 and 2005 when he was in a position of authority?” she was quoted by The Irish Times as saying.

“It will be immeasurably damaging to both survivors and the Catholic Church if this process is dragged out indefinitely.

“We call on all concerned to provide real moral leadership by finding the courage to acknowledge responsibility for their actions and inactions and to resign immediately.”

Two more bishops resigned on Christmas Eve. Eamonn Walsh and Raymond Field were among the clergy named in the Murphy report for their failure in handling allegations of child abuse within the Archdiocese of Dublin. They apologised to victims in a joint statement.

“It is our hope that our action may help to bring the peace and reconciliation of Jesus Christ to the victims/survivors of child sexual abuse. We again apologise to them,” they said.

“Our thoughts and prayers are with those who have so bravely spoken out and those who continue to suffer in silence.”

Their resignation follows that of the Bishop of Kildare James Moriarity last week and the Bishop of Limerick Donal Murray earlier in the month. The report found Murray’s failure to deal with a priest suspected of child abuse “inexcusable”.

Archbishop Diarmuid Martin told Roman Catholics in St Mary’s Pro-Cathedral in Dublin that 2009 had been a painful year for the Church.

He said: “The diocese failed its most vulnerable members. The archdiocese failed to recognise what was to be done.”