THE Dean of St Edmundsbury Cathedral, the Very Revd Frances Ward, became embroiled in a political storm this week, after she wrote a letter urging the local Conservative MP to resign because he had assaulted his former partner.

David Ruffley, MP for Bury St Edmunds, was arrested by police at a house in central London in March, and later accepted a caution for common assault. After more than a week of calls for his resignation, Mr Ruffley said on Monday evening that he would retire at the next election.

In a letter to the Conservative Party, he said that while he considered the matter closed, since he had apologised, the "protracted media debate" was a distraction. In a statement two weeks ago, Mr Ruffley admitted that there had been an "incident" involving his former partner, resulting in "inappropriate action on my part, which I deeply regret".

Demands for his resignation increased, however, after it emerged that Dean Ward, who is a friend of Mr Ruffley's former partner, had written to him accusing him of downplaying the altercation, and misleading her.

In the letter, Dean Ward wrote: "You tried to convince me that . . . there was blame on both sides. When I visited [Mr Ruffley's former partner] in March, a day or so after the event, and went to hug her . . . she winced in obvious pain.

"She told me, as a friend and her priest, of the events of the evening that had led to your arrest, and how frightened she had been of your rage and violent behaviour. . . I cannot let you try to tell me that it was only a 'little local incident', or that she was at fault."

The Dean's letter ends with her suggesting that Mr Ruffley seek professional help for his "health and well-being", and that he considerhis position as MP for Bury St Edmunds. The letter was also sent to the Chief Whip Michael Gove, the acting Bishop of St Edmundsbury& Ipswich, the Rt Revd David Thompson, and the Chief Constable of Suffolk Constabulary, among others.

After the publication of the letter, Dean Ward issued a statement that confirmed that the leaked letter was accurate, and that she had nothing further to say.

In his first statement, Mr Ruffley said that he had apologised to his former partner, and that the matter had been dealt with by the police at the time. "I wish to stress that I would never condone domestic violence under any circumstances," he said.

The local Conservative Party brought forward its annual meeting from September to 31 July to allow its members to discuss the issue. Senior Tory figures in Suffolk had also criticised Mr Ruffley; they included the county's police and crime commissioner, Tim Passmore, who said that Mr Ruffley's behaviour was "inexcusable".

"In my opinion there cannot and must not be any hiding-place for the perpetrators of such brutal crimes," he said in a statement two weeks ago. Local anti-domestic-violence charities had also called for Mr Ruffley's resignation, and an online petition on the same subject had gathered tens of thousands of signatures.

One member of the local Conservative association, Bernard Sergeant, told the BBC's Jeremy Vine Show on Monday, however, that most domestic issues behind closed doors were "six of one and half-a-dozen of the other". "Nobody really knows what went on. I'm surprised that the Dean should take this situation and publicly become judgemental."

When asked if he would be happy having a man who had beaten up his girlfriend as an MP, Mr Sergeant replied: "Well, why not? There are very few people in life who havenot done something that they subsequently regret. They shouldn't vilify the man."

Despite some backing from his local association, however, Mr Ruffley said he would reluctantly resign next year. His decision not to stand down until the 2015 election means that the Conservatives do not have to fight a by-election. Bury St Edmunds is a safe seat, Mr Ruffley holding a majority of 12,380.