St Saviour’s on Mortomley Lane has a capacity of fewer than 200 - and so many mourners are expected, the service is to be relayed by video-link to the nearby St Mary’s Catholic Church too.
Canon Bessant is also in talks with police, the council, schools, bus operators and the undertaker about numbers expected, as Mortomley Lane is a busy route.
“We are expecting large numbers, and we want to make sure we do this properly,” he said.
Mr Greaves was an organist, pianist, lay preacher and retired social worker, and Canon Bessant predicted musicians, churchgoers, former colleagues and locals would all want to pay their respects.
“I think there will also be a lot of people who did not know him at all,” said Canon Bessant.
“I have received so many cards and emails to pass to Maureen from all around the country, from people who did not know Alan but who wanted to express their feelings.”
Mr Greaves also volunteered at St Paul’s Church in Parson Cross. A warden there said a huge turnout is expected at the funeral.
“There will be a lot of people,” said the warden. “Maureen says anyone can go. It’s not going to be a solemn occasion - it’s going to be a celebration of Alan’s life.”
n Two men - Jonathan Bowling, 22, and Ashley Foster, 21 - have been charged with Mr Greaves’ murder.