The Archbishop of Canterbury is due to join the Pope at the Vatican on Saturday.

It could be a frosty affair as it is the first time Dr Rowan Williams and Benedict XVI have seen each other since the latter invited disenchanted Anglicans to become members of his Roman Catholic church.

The creation of personal ordinariates was a surprise announcement - Dr Williams was given only two weeks' notice - and it could lead to thousands across the world converting to Catholicism while retaining parts of their former Anglican heritage.

The pair will hold a private meeting at the Vatican and that subject will certainly be discussed - but the Archbishop has tried to play down the significance of the offer.