Leading peer and QC Baroness Helena Kennedy has spoken of the "huge compassion" she feels towards Cardinal Keith O'Brien after his admission his sexual conduct had "fallen beneath the standards" expected of him.

Lady Kennedy said it was "torture" for the Roman Catholic Church to force priests who wanted to have a sex life to be celibate as she spoke at a news conference calling for the church's reform.

"I feel very sad for Cardinal O'Brien because here was a man who quite clearly had wanted to have a sexual life and felt that it was a failing for him to want to have a sexual life and that he was going against his commitment to celibacy," she said.

"It is terrible to torture people by expecting that of them and I just feel huge compassion for him. I do not like the idea that there might be an issue of being predatory but I do not want to make a judgment on that."

Lady Kennedy's remarks come after Cardinal O'Brien resigned last week as Archbishop of St Andrews and Edinburgh amid allegations of "inappropriate behaviour" towards three serving priests and one former priest.

This weekend Cardinal O'Brien admitted his sexual conduct had "fallen beneath the standards" expected of him and asked forgiveness of those he had offended.

Lady Kennedy, who was brought up in Glasgow as a Catholic, spoke at the launch in the House of Commons of the Catholic scholars declaration on authority in the Church.

Lady Kennedy said she backed the Catholic Church's work in areas such as alleviating poverty and its stance on opposing the Iraq war.

But she said there had been "serious crises" in the Catholic Church and it faced issues of "transparency, accountability and governance".