Bishop administrator Peter Stuart will conduct the service that will bring to an end more than 155 years of history in the village.

St Clement's, the Hunter's second oldest church, was built in 1843 and consecrated in 1855.

Its future has been under a cloud since 2008, when an arson attack forced its closure.

Parishioners, who paid the church's insurance premiums for many years, have fought to have it restored for services.

But the diocese argued a $375,000 insurance payout would not cover the repairs and likely costs and should be spent on other churches in the area.

Wendy Noble, who has five generations of her family buried in the church's cemetery, will wear black at Sunday's service.

"I'm absolutely disgusted with what's happened," she said.

"The [former] bishop shook my mother's hand the day after the fire and said 'Don't worry we will restore the building'," she said.

Former St Clement's warden Graeme Cheetham said he would not attend the service.

"It's an absolute disgrace," he said.

Bishop Stuart said he recognised the sadness some were feeling about the deconsecration of St Clement's.

"We will be praying for them and offering thanksgiving for the ministry that has occurred from there on Sunday at 2pm," he said.

St Clement's will be maintained as a historic site.

The adjoining cemetery will remain open to the public.

Heritage Minister Robyn Parker said in May she was powerless to intervene.

St Clement's was not eligible for a state grant because it was not listed on the state heritage register.