The canon chancellor of St Paul's Cathedral, the Rev Dr Giles Fraser, has resigned in protest at plans to forcibly remove protesters from its steps, saying he could not support the possibility of "violence in the name of the church".

Speculation grew in the last 24 hours that Fraser, a leading leftwing voice in the Church of England, would resign because he could not sanction the use of police or bailiffs against the hundreds of activists who have set up camp in the grounds of the cathedral in the past fortnight.

Just after 9am on Thursday, Fraser tweeted: "It is with great regret and sadness that I have handed in my notice at St Paul's Cathedral."

In a statement to the Guardian, Fraser, who was appointed canon in May 2009, confirmed his resignation, saying: "I resigned because I believe that the chapter has set on a course of action that could mean there will be violence in the name of the church."

He is expected to take part in a service at St Paul's on Friday afternoon, the first since the cathedral closed its doors a week ago for health and safety reasons.

The dean of St Paul's, the Right Rev Graeme Knowles, said he was "very sorry" to see Fraser leave.

"Giles has brought a unique contribution to the life and ministry of St Paul's and we will be very sorry to see him go. He has developed the work of the St Paul's Institute and has raised the profile of our work in the City.

"We are obviously disappointed that he is not able to continue to his work with Chapter during these challenging days. We will miss his humour and humanity and wish Giles and his family every good wish into the future."

Fraser quickly became a hero figure among the Occupy the London Stock Exchange (LSX) movement, clearing police officers off the steps of St Paul's and supporting the group's right to peaceful protest after a court injunction stopped it from setting up camp in nearby Paternoster Square. He also delivered a Sunday sermon decrying corporate greed, which was seen as another sign of his endorsement of the protest.

Occupy London said it was "deeply moved" to hear of his resignation.

"He is man of great personal integrity and our thoughts are with him. He respected our right to protest and defended it. For that we are very grateful, as he ensured that St Paul's could be a sanctuary for us and that no violence could take place against peaceful protesters with a legitimate cause – challenging and tackling social and economic injustice in London, the UK and beyond."

A spokeswoman, Naomi Colvin, added: "Courage like that is really very inspiring. It reassures us that what we're doing is important. The people who have a bit of integrity, it's becoming more obvious who those people are. I hope we can do well enough to justify their sacrifices."

Fraser baulked at the idea of the church forcibly evicting the hundreds of people who have built the "tent city", a likely outcome given the intense discussions happening within the cathedral and the City of London Corporation. Some at St Paul's are said to be unhappy about the increased pressure from the Corporation of London and the London mayor, Boris Johnson, to have Occupy LSX protesters removed from one of the city's most popular tourist attractions.

The City of London Corporation, which is the local authority for the Square Mile, is meeting on Thursday to discuss plans for any eviction. A formal meeting will take place on Friday, when the corporation's planning and transportation committee considers advice on how to resolve the deadlock.