VATICAN CITY — Cardinal Keith O'Brien, Britain's highest-ranking Catholic leader, said Monday he wouldn't take part in the conclave to elect the next pope after being accused of improper conduct with priests — an unprecedented first head to roll in the mudslinging that has followed Pope Benedict XVI's decision to resign.

Benedict accepted O'Brien's resignation as archbishop of St. Andrews and Edinburgh — submitted back in November because he is due to turn 75 next month, the normal retirement age for bishops. But simultaneously, O'Brien issued a statement Monday saying he would also skip the conclave because he didn't want to become the focus of media attention at such a delicate time for the church.

O'Brien has said through his spokesman that he is contesting allegations made Sunday in a British newspaper that three priests and a former priest have filed complaints to the Vatican alleging that the cardinal acted inappropriately with them. The Observer newspaper did not name the priests, but it said their allegations date back to the 1980s. There were no details about the alleged inappropriate behavior.