Police will maintain a buffer zone between protesters and the thousands of mourners expected to attend the funeral service for Cardinal George Pell at St Mary's Cathedral.
The former Catholic archbishop of Melbourne and Sydney will be laid to rest after an 11am requiem mass on Thursday, following his death in Rome last month at 81.
Former prime ministers John Howard and Tony Abbott and Opposition Leader Peter Dutton are expected to be among the mourners but neither NSW Premier Dominic Perrottet nor Opposition Leader Chris Minns will attend the service for the controversial figure.
Thousands of colourful ribbons attached to the cathedral's gates in memory of those who suffered sexual abuse by clerics were removed overnight.
Police initially tried to block the protest outside the cathedral by LGBTQI group Community Action for Rainbow Rights, before a compromise was reached late on Wednesday.
Protest organisers agreed not to march on College Street directly next to the cathedral but will be allowed to gather on the other side of the road within earshot of mourners.
Acting Assistant Police Commissioner Martin Fileman said the buffer zone would help mitigate the potential for clashes between protesters and mourners.
"We ask that people attending, on both sides, (be) respectful of each other," he said.
Cardinal Pell's conservative stance on issues including gay marriage and abortion rights had been the subject of staunch criticism, and he faced allegations of covering up child abuse.
Protest organiser Kim Stern said the rally would be peaceful but "loud, vibrant and visible".
"It's a real slap in the face of survivors that they have taken the ribbons off but it's really important that we keep the pressure on the Church," he told ABC TV on Thursday.
Cardinal Pell was the Vatican's top finance minister before leaving Rome in 2017 to stand trial in Melbourne on child sexual abuse offences.
He was convicted the following year of molesting two teenage choirboys in the sacristy of Melbourne's St Patrick's Cathedral while archbishop in 1996.
Cardinal Pell maintained his innocence and in 2020 his convictions were quashed by the High Court.
© AAP 2023