The Catholic Archbishop of Adelaide Philip Wilson faces unprecedented calls to resign from across political arena as he prepares to challenge his conviction for concealing child sexual abuse.

Wilson, 67, is the most senior Catholic official in the world to be found guilty of such a crime. Earlier this week, he sentenced to 12 months in jail with a six-month non-parole period.

The cleric announced on Wednesday night he would appeal his conviction for the offences committed in the Newcastle region between 2004 and 2006. He plans to resign only if that fails.

But South Australian Premier Steven Marshall has joined Prime Minister Malcolm Turnbull and federal Opposition Leader Bill Shorten in calling for Wilson to resign immediately.

“He’s been convicted, he’s been sentenced. I think it’s untenable to remain in that position,” Mr Marshall was quoted as saying in The Advertiser on Thursday.

NSW Police Minister Troy Grant, a former police officer who was involved in investigations into child abuse in the Maitland-Newcastle area in 1995, said the sentence handed to Wilson was appalling.

“This is no deterrent as a sentence, it’s appalling, the children deserve better, the victims deserve better, and the community do,” Mr Grant told 2GB Radio.

Wilson is in line to potentially serve his sentence in home detention, pending the appeal proceedings.

On Wednesday, Wilson said he would not quit his post, despite the growing calls.

“I intend to lodge an appeal against my conviction to the District Court of New South Wales,” he said in a statement.

“I am conscious of calls for me to resign and have taken them very seriously.

“However, at this time, I am entitled to exercise my legal rights and to follow the due process of law.

“Since that process is not yet complete, I do not intend to resign at this time.”

In May, after a landmark magistrate-only trial in Newcastle Local Court, Wilson was found guilty of failing to report to police the historical sexual abuse of two altar boys by a paedophile priest.

He confirmed on Wednesday he would lodge an appeal to the NSW District Court.

Father Frank Brennan, chief executive of Catholic Social Services Australia, said Wilson should step down “for the good of everyone” after a difficult week for the Catholic Church and victims.

“You’ve been already four or six years before the courts, you’re going to have another year or two before the courts,” he told Sky News.

“You’re not do anything to help the Archdiocese of Adelaide, you’re not doing anything to help the victims, you’re not doing anything to help the Australian community heal after what we’ve been through with the royal commission.”

In sentencing last week, Magistrate Robert Stone said “there is no remorse or contrition showed by the offender”.

“I am of the opinion the sentence should not be suspended. It does not support the terms of general deterrence,” Mr Stone said.

“On that basis, the only available remaining option is full-time imprisonment or home detention.”

-With AAP