A Conservative MP who was once the shadow police minister is to stand down at the 2015 general election after being given a police caution for assault against an ex-partner. The news comes as Labour unveils plans to set up a shake-up of laws around domestic abuse.

David Ruffley, who has represented the Suffolk constituency of Bury St Edmunds since 1997, said that although his ex-girlfriend had apparently forgiven him, the subsequent media storm was detrimental to his party.

In a letter to the Conservative party Ruffley said: "Sadly, although I have apologised for a very regrettable incident last March and both my former partner and I considered the matter closed, I have reluctantly come to the conclusion that a protracted media debate on my private life, whatever the motivation or however misinformed, would not serve the wider interests of the Conservative cause in East Anglia. Nor at a human level am I prepared to continue to sustain the unrelenting orchestrated intrusion into my personal life."

Michael Gove
New Tory chief whip Michael Gove was forced to take action over David Ruffley\'s caution Reuters

It is thought Ruffley had hoped to ride out the storm - with the support of several local Conservatives including Bernard Sergeant - until the Dean of St Edmundsbury Cathedral, the Very Rev Frances Ward intervened.

In a letter to Ruffley also sent to Conservative chief whip Michael Gove Ward said Ruffley's position had become untenable: "It is my belief that you have lost the confidence of a significant proportion of your former supporters and should consider your position."

Ward, a friend of Ruffley's ex-partner, described how when she hugged the woman in question a few days after the incident in a London flat Ruffley's ex had been "wincing in obvious pain". A petition on Change.org calling for Ruffley to resign was signed by some 38,000 people. Suffolk's Conservative police and crime commissioner, Tim Passmore also said he thought Ruffley's behaviour was "inexcusable" - and Mr Gove, handed the post following the recent cabinet shake-up, appears to have accepted he had no choice but to stand aside.

"David Ruffley MP has given a huge amount to Parliament both on the Opposition Front Bench and as an outstanding member of the Treasury Select Committee," said Gove in a statement. "I am sorry that he will be standing down at the General Election in May 2015, but fully respect his reasons."

Bolton-born Mr Ruffley, 52, is a Cambridge graduate who became a solicitor before entering politics. In 2010 he was treated for minor injuries when he jumped under a train at Victoria station. He was said at the time to be suffering from acute depression after being exposed in the expenses scandal.