Anti-capitalist protesters outside St Paul's Cathedral could remain in place for months despite pleas that the church and local businesses are suffering as a result.
The cathedral is losing thousands of pounds per day as a result of being forced to close over health and safety concerns about the protest camp on its doorstep.
A second site has been established on Finsbury Square in Islington in order to ease numbers, but activists outside St Paul's have pledged to remain there indefinitely.
Their renewed enthusiasm came as thousands of Sunday worshippers were turned away at an estimated cost of more than £20,000.
A spokesman for the cathedral said that businesses in the vicinity were also suffering because of the protest camp. He said: "There are a lot of people in that area who are also concerned about the timetable. A lot of independent traders are being affected and that whole part of London is not easily accessible."
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, 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.
The Occupy London supporters have refused to comply with a public request to move on - with some digging in at the foot of St Paul's and another group of around 100 people setting up camp on Finsbury Square.
Jo, 41, who took up position at the steps of the historic monument, said she was prepared to continue her battle indefinitely. The unemployed activist, who has no fixed address and declined to give her surname, added: "I'll be sitting here until there's real evidence the underlying system that allows a few to get very rich while others starve will change."
Members of protest group UK Uncut said they would join with the Occupy London Stock Exchange supporters at St Paul's at midday before marching to the head office of Her Majesty's Revenue and Customs (HMRC) in Whitehall. The demonstrators plan to demand the resignation of HMRC deputy chief executive Dave Hartnett, accusing him of allowing Vodafone and Goldman Sachs to avoid making certain payments.