RELATIONS between conservative clergy and parishioners in the troubled St Vincent's parish in Redfern have taken another dramatic twist, with a church tribunal finding that an assistant priest defamed a parishioner.

In an unusual case, the Ecclesiastical Regional Tribunal for NSW, a key church judicial body, has upheld a complaint against a former assistant priest, Dennis Sudla.

Clare Maguire claimed her right to a good reputation had been violated by Father Sudla, a neocatechumenal priest.

The tribunal's finding was this week posted on the parish's community blog, The Church Mouse, and confirmed by the offended parishioner.

Ms Maguire declined to elaborate on the priest's behaviour but told the Herald the matter came to a head over an exchange in the presence of witnesses during Mass, while she was stepping forward to put flowers on the altar to commemorate Hiroshima Day.

Before lodging her complaint, Ms Maguire said she had approached nine different levels of the church hierarchy and each time was redirected to Cardinal George Pell.

"I'm very satisfied. But were this a civil case, there would have been a very large financial compensation for the content of his words," she said.

Ms Maguire said the judgement had yet to be executed but in part required a financial sum to be paid towards the costs of Sharing of the Meal, which is the parish's twice-weekly provision of meals and hospitality for people in Redfern.

Yesterday, in a separate matter, parishioners issued an open letter to Father Gerry Prindiville, accusing him of walking out of Mass last Sunday because he regarded the words of the Offertory song to be political.

Parishioners said the parish clergy had also ignored and ridiculed lawful parish customs and claimed it had turned away some Aborigines from the altar. They also defended their right to bring issues such as the plight of Aborigines and asylum seekers to the liturgy.

Last week Father Prindiville appealed to parishioners to co-operate with him so he could carry out his parish role.