St Paul's Cathedral is to remain closed for the foreseeable future amid fears the anti-capitalist camp on its doorstep could threaten Christmas services.
Activists have refused to budge from their position at the foot of the London landmark, with many pledging to remain on-site indefinitely.
Their renewed enthusiasm came as thousands of Sunday worshippers were turned away at an estimated cost of more than £20,000.
The demonstration - which has now spread to nearby Finsbury Square in Islington - has sparked concerns that local businesses could suffer.
The cathedral has started talks with a number of neighbouring organisations, a spokesman said, as activists reiterated plans to continue their fight.
"There are a lot of people in that area who are also concerned about the timetable," the spokesman added. "A lot of independent traders are being affected and that whole part of London is not easily accessible. This is no longer just about St Paul's and it is not something we can deal with on our own."
Faced with the question of whether Christmas programmes could be cancelled, he said: "It isn't impossible that that will be the case."
A number of fixtures - including an All Saints' Day service on November 1 and hundreds of special charity services in the run-up to Christmas - could be threatened by the action.
With no prospect of St Paul's reopening, Monday's Evensong has been moved to Southwark Cathedral.
St Paul's has been losing valuable funding since it shut its doors on Friday for the first time since the Second World War. This followed concerns the Occupy London campaign posed a health and safety risk.