Leaders' praise for Pope
David Cameron and Ed Miliband have sent their regards to Pope Benedict XVI after the Vatican confirmed the Pope will resign later this month.
The Prime Minister said: "I send my best wishes to Pope Benedict following his announcement today.
"He has worked tirelessly to strengthen Britain's relations with the Holy See. His visit to Britain in 2010 is remembered with great respect and affection. He will be missed as a spiritual leader to millions."
The Labour leader said: "His decision to stand down is a brave one and we know he will not have reached it lightly. The choice of a successor is clearly an important one for the Catholic church.
"Our thoughts are with those who must make such a critical decision on behalf of millions around the world."
The Pope will retire on 28 February. Pope Gregory XII was last Pope to resign in 1415.
In a statement put out by the Vatican, the Pope declared: "After having repeatedly examined my conscience before God, I have come to the certainty that my strengths, due to an advanced age, are no longer suited to an adequate exercise of the Petrine ministry."