by Joe Walker

The Archbishop of Canterbury has today told of his "heavy heart" after learning of the Pope’s shock decision to resign.

The Most Rev Justin Welby, who took up the post officially last week, was speaking after Pope Benedict XVI stunned the world with his declaration this morning.

The move, announced without warning and believed to be because of ill-health, will take place on February 28 and leave the papacy vacant until a successor is chosen.

The Most Rev Welby said: "It was with a heavy heart but complete understanding that we learned this morning of Pope Benedict’s declaration of his decision to lay down the burden of ministry as Bishop of Rome, an office which he has held with great dignity, insight and courage.

"As I prepare to take up office I speak not only for myself, and my predecessors as Archbishop, but for Anglicans around the world, in giving thanks to God for a priestly life utterly dedicated, in word and deed, in prayer and in costly service, to following Christ.

"He has laid before us something of the meaning of the Petrine ministry of building up the people of God to full maturity."

Benedict, who became the 265th pope in 2005, has arthritis, particularly in his knees, hips and ankles. He had been due to travel to Brazil in July for a youth festival, but concerns had been raised about whether he was well enough.

The Most Rev Welby said: "In his visit to the United Kingdom, Pope Benedict showed us all something of what the vocation of the See of Rome can mean in practice – a witness to the universal scope of the gospel and a messenger of hope at a time when Christian faith is being called into question.

"In his teaching and writing he has brought a remarkable and creative theological mind to bear on the issues of the day.

"We who belong to other Christian families gladly acknowledge the importance of this witness and join with our Roman Catholic brothers and sisters in thanking God for the inspiration and challenge of Pope Benedict’s ministry.

"We pray that God will bless him profoundly in retirement with health and peace of mind and heart, and we entrust to the Holy Spirit those who have a responsibility to elect his successor."