Protesters have continued to occupy the ground outside St Paul's Cathedral after the church was forced to close its doors to members of the public because of the anti-capitalist protest taking place in its churchyard.
The Occupy London Stock Exchange demonstration, which started on 15 October, has seen protesters camp out near to Paternoster Square in the shadow of Wren's iconic building.
More than 300 tents are currently pitched outside the cathedral.
The Dean of St Paul's, Rev Graeme Knowles, said: "We have a legal obligation to keep visitors safe and healthy," adding that the decision to close the doors was made "with a heavy heart".
The cathedral, which hasn't closed its doors on the public since World War II, will shut after the Friday afternoon service.
The Dean called the move "unprecedented in peacetime".
"The health and safety, and fire offices have pointed out that access to and from the cathedral is seriously limited," he said.
"With so many stones and fires and types of fuel around there is a very clear fire hazard."
Ronan McNern, one of the protesters, told the BBC that there were rumours that the church's hand had been forced.
"They've cut off all dialogue, what had been good dialogue," McNern told the BBC. "We're questioning whether pressure has been put on them in certain ways."
The Occupy London Stock Exchange group argue that they have co-operated with fire authorities, and said they will seek clarification about the health and safety issues while continuing to protest.
In a statement issued on Friday afternoon the protesters said they were disappointed that the Cathedral had closed.
"Since the beginning of the occupation six days ago, OccupyLSX have tried hard to accommodate the Cathedral’s concerns in any way we can," they said,
"Over the past 48 hours, we have completely re-organised the camp in response to feedback from the Fire Brigade and we have also accepted the presence of two large barriers to preserve access to the side door of the Cathedral.
They added: "We also understand that some individuals were in the process of arranging for a contribution to be made to St Paul’s in recognition of their hospitality.
"It is a shame the Cathedral authorities have decided to take this action before those preparations came to fruition, as we expected them to in the next 12 hours.
"Over the course of this week, we have done a huge amount to draw attention to the crisis of economic and political legitimacy experienced in the UK and mirrored in protests staged across the world.
"That awareness-raising exercise – and our attempts to provide a truly participatory and accountable forum in which to investigate ways forward – will continue."
Bookmaker William Hill is offering odds of 100/1 that the building will still be closed to the public on Christmas Day.
A wedding, which was scheduled to take place on Saturday, will still go ahead, the Dean said.
Outside, the activists said they would throw the couple a party.
Here, The Huffington Post UK offers a history of one of London's most famous landmarks: