St Paul's Cathedral is to reopen, a week after anti-capitalist protesters forced it to close for the first time since the Second World War.

The cathedral doors will open in time for the Eucharist at 12.30pm, which will include a prayer for the protesters camping outside.

The reopening follows the resignation of cathedral chancellor Canon Dr Giles Fraser on Thursday, who quit because he feared plans to evict the protesters could lead to violence.

The former Archbishop of Canterbury George Carey described the situation as a "debacle", which was threatening to damage the reputation of Christianity.

The Dean of St Paul's, the Rt Rev Graeme Knowles, said officials were considering all options in response to the protest, including the courts. The City of London Corporation, the local authority for the Square Mile, is expected to meet to hear legal advice and decide whether to launch eviction proceedings.

Writing in the Daily Telegraph, Lord Carey criticised both the "mismanagement" of the situation by St Paul's authorities and the "self-indulgence" of the protesters. He said the cathedral authorities "seemed to lose their nerve" after initially welcoming the protesters, adding: "One moment the church was reclaiming a valuable role in hosting public protest and scrutiny, the next it was looking in turns like the temple which Jesus cleansed, or the officious risk-averse 'elf and safety bureaucracy of urban legend. How could the dean and chapter have let themselves get into such a position?"

He accused the demonstrators of being "cynical and opportunistic" and said a picture had emerged of "spoilt middle-class children returning home at night for a shower and a warm bed".

In his article, Lord Carey described Dr Fraser's resignation as a "sad day" for the cathedral. Dr Fraser, who has been sympathetic to the campaigners, quit following proposals that the church join forces with the Corporation of London to take legal action to remove the camp.

He said he could not tolerate the possibility of an eviction similar to that at the illegal travellers' site at Dale Farm, telling the BBC: "I resigned because I believe that chapter was set on a course of action that could ultimately lead to violence, to eviction, to protesters being forcibly moved on."

The former vicar of Putney said he had no criticism of those at St Paul's who held a different view, telling the Times: "They, too, are making principled stands for what they believe in. At no point has anyone asked me to leave."