About 250 demonstrators appealed for donations of sandbags, wooden palettes and tarpaulins as organisers made plans to create a semi-permanent camp outside the cathedral.
The third day of rallies against what the activists called “corporate greed” passed without any arrests, however, as City workers returned to their desks after the weekend.
Demonstrators, who had earlier been unable to disrupt the London Stock Exchange, outlined plans to set up a kitchen, a visitors’ centre and a shelter in which to hold “general assemblies” – the open meetings used to make decisions about their strategy.
Occupy LSX published an online manifesto but many passing City staff said they were still unclear about the group’s aims.
Its placards ranged from anti-capitalist slogans to criticism of the coalition’s planned NHS reforms. A construction company director, 44, who did not want to be named, said: “I am still trying to work out what the objective is.”
As protesters invited City workers to “come and join us”, one chartered accountant drew a crowd of onlookers when he attacked the banking bailout of 2008.
Tim Sanders, 45, said: “The general public has to understand the meaning of ‘too big to fail. Capitalism without bankruptcy is like Christianity without hell.”
Kai Wargalla, 26, a student and activist, originally from Germany. said: “We need politicians and people working in the financial industries to come to us and talk to us. I hope City workers will come to support.”
Services at St Paul’s took place as normal but the cathedral said the last few days had not been without “various challenges”.
Shopping centre One New Change said it was working with the police but had not been affected. The LSE declined to comment.