Pope Benedict has made it easier for disaffected Anglicans to convert to Roman Catholicism.

Rowan Williams, the Archbishop of Canterbury and spiritual head of the Anglican Church, and Vincent Nichols, Archbishop of Westminster and head of the Catholic Church in England and Wales, stressed dialogue would continue between the two churches.

They were at pains to say it was not a comment on the Anglican Communion, but a response to requests from traditional Anglicans from all over the world.

Williams said he did not see it as an act of aggression, but he had no input in the new "Apostolic Constitution" and was only told about its details two weeks before it was disclosed at the offices of the Roman Catholic Church in London. A simultaneous press conference was held at the Vatican.

The head of the Anglican Church has been trying to keep together the liberal and conservative wings of the church, divided since the consecration of openly gay U.S. Bishop Gene Robinson in 2003 and the blessing of same sex marriages in Canada.

The Church of England has also experienced disagreement over the issue of women bishops.

Details of the legal framework were limited, but the constitution allows groups to join the Roman Catholic Church while maintaining some of their own traditions.

It allows for the ordination as Catholic priests of married former Anglican clergy, but not bishops.

It would allow the appointment of leaders, usually bishops, to oversee communities of former Anglicans who become Catholics and recognise the pope as their leader.

They may be able to eventually develop their own liturgy which would have to be approved by the Holy See.

The constitution poses serious questions for both churches.

For the Anglican Church, will it weaken its status? Will it clear the way for women bishops?

For the Roman Catholic Church, will it reopen the issue of celibate priesthood?

The Church of England should shed its "booted and suited" middle-class image, a British bishop says.

"Even today I meet people who think you have to be highly educated or suited and booted to be a person who goes to church" the Reverend Stephen Cottrell, Bishop of Reading, in southern England, said.

The comments come as Christian churches throughout the UK and other parts of the world launch a week-long "back to Church Sunday" campaign, an attempt to encourage people of all social classes to go to church this Sunday.

Up to 16,000 Church of England churches as well as Churches Together in Scotland, the Church in Wales, Baptist, Methodist, United Reformed, Salvation Army and Elim Pentecostal churches will be taking part as will Anglican churches in Australia, Argentina, New Zealand and Canada.

A poll in 2007 showed the social breakdown of congregations in Britain was evenly spread, but drawing on a shopping analogy, the Bishop likened the church's image to that of middle-class Marks & Spencer rather than the more downmarket supermarkets Asda and Aldi.

"How did it come to this, that we have become known as just the Marks and Spencer option when in our heart of hearts we know that Jesus would just as likely be in the queue at Asda or Aldi? " he asked.

"That's so frustrating. Jesus got us started with church simply. Like this: sitting us down in groups on the grass and telling simple stories. Not simplistic. But certainly not complicated. All his first disciples were down-to-earth people who wanted to know what life was all about."

He said churches were places of "warmth and honesty...Not a hobby but a way of life".

"Church: it’s definitely not about how you look, what you do, how you sound, how well you sing. Just come as you are," he added.

A YouTube invitation has been posted by the Bishop of Sheffield, the Revd Steven Croft, and local radio adverts have been placed, while a Nottinghamshire bishop, the Revd Tony Porter, will be donning his biking leathers and setting off for a Territorial Army barracks to deliver the invitation.

Rowan Williams, the Archbishop of Canterbury and the spiritual head of the Anglican Church, backed the campaign, saying the church had a responsibility to welcome all comers.