NORTH Wiltshire MP James Gray has said he will not resign over an affair with countryside campaigner Philippa Mayo.

He admitted the 19-month affair yesterday, saying that his 51-year-old wife Sarah is to leave him.

He told her about his relationship with 44-year-old Mrs Mayo, who is married with three young children, three weeks ago.

Mr Gray, 52, said: "I very much regret the pain I have caused but it is true that I have a continuing relationship with Philippa Mayo and I hope that in the fullness of time we will be married.'' He met Mrs Mayo in February 2005 at a meeting in Rutland of the Vote Okay campaign group where Mr Gray was a speaker. Mrs Mayo was a voluntary member of the group.

In April his wife Sarah was diagnosed with breast cancer. During the General Election campaign later that year he asked for prayers for her during a church election meeting and in November that year referred to her fight against the illness in a speech to Parliament about availability of the drug Herceptin.

Mrs Gray was told the cancer was in remission in February and has had two successful check-ups since.

He is prepared for calls for him to quit the post as MP he has held since 1997.

But he said: "I will not be resigning nor is there any possible reason why I should do. I have been elected to represent the interests of the people of North Wiltshire in Parliament and hold the Government to account and I hope that I do a reasonable job of doing both things and I will continue to have the opportunity to do so.

"And therefore the sadness of what is happening in my private life should not affect my ability to carry out my duties precisely as before.

"I know that some political opponents may call for me to resign but that is to seek to take party political advantage out of somebody else's private life.

"I hope that despite all of this people of North Wiltshire are happy for me to continue to represent them for another 20 years.'' He is also prepared for criticism about carrying on the affair while his wife was fighting cancer, and for referring to her illness during the election.

He said: "At one of the church dos in Chippenham a local minister asked if you had the opportunity to ask for everyone's prayers, what would you ask them to pray for' and I said I am very sorry I can do no other than ask to pray for Sarah who has got cancer'.

"I certainly did not use her illness as part of an election campaign and nor would I.'' He insists that his relationship with Mrs Mayo is genuine. "Philippa and I intend at some stage in the future to marry when the circumstances permit. I regret the damage caused but this was not a whim,'' he said.

His wife Sarah has been on holiday for the past week with their daughter Olivia, 19. They have two other children, John, 22, and William, 15.

"I have told the children what is happening and obviously it is painful but they are okay,'' said Mr Gray.

"I am not proud of myself in the sense that these things cause a great deal of pain.

"The only thing I am concerned about is the family. Sarah has been clear of the cancer for six to nine months. I wanted to see her through that.

"I am not proud of it, an affair is nothing to be proud of. But what's happened has happened and Philippa and I are very much in love.'' He said the pressures of parliamentary life can put a strain on any MP's marriage.

"Parliamentary life is very difficult,'' he said. "I spend a number of days a week away. When Parliament is sitting it is four days a week away in London and even now during the recess it is two days a week in London.

"Sarah is away quite a lot visiting friends and family. When you add in foreign travel and party conferences we are apart a very great deal and have been for ten years.'' But he added: "Sarah is blameless in all of this, she is a very nice woman. I hope that she and I will remain friends in the future. She is a good person, a good mother and very popular within the Conservative Association and of course I deeply regret the pain this has caused her and the children.'' The Gazette understands Mrs Gray, who originally comes from Winchester, will be moving out of the family's cottage in Slaughterford and buying a new home elsewhere.

Mr Gray will also eventually put the family's cottage on the market and buy another home in the area.

This week he told Roger Miller, chairman of the North Wiltshire Conservative Ass-ociation, and, while in London, Patrick McLoughlin the Tory chief whip about the affair and his marriage break-up.

"I told them what had happened and said I don't think this should affect my career at all.

"They both said they were very sorry it had happened and that they understood,'' he said.