VANCOUVER — A polygamy charge against the leader of a fundamentalist, Mormon breakaway commune in southeastern British Columbia is unfair and should be thrown out because he wasn’t given “fair notice,” a court has heard.

But the Crown wants Winston Blackmore’s petition dismissed, saying arguments about fairness belong in a criminal trial.

Blackmore is one of the heads of Bountiful, B.C. — a remote, fundamentalist community whose name has become synonymous in Canada with the practice of polygamy.

Blackmore’s lawyer Joe Arvay argued in B.C. Supreme Court on Monday that the provincial government doesn’t have the right to criminally charge his client — or any resident of Bountiful — for historical acts of polygamy.

The cutoff point, said Arvay, should be a 2011 reference question that concluded polygamy laws do not violate the Charter of Rights and Freedoms. That decision provided constitutional clarity to Canadians involved in the controversial practice, he added.

“The whole point of having a reference (case) was to give … those people fair notice that their conduct was lawful or unlawful,” Arvay said.

“It would be unfair to the people of Bountiful to prosecute them for conduct that they were led to believe by many people in authority … was lawful.”

Crown lawyer Karen Horsman countered Arvay’s argument, saying that to exempt historical acts of polygamy from prosecution would tie the province’s hands and “grandfather” Blackmore’s alleged polygamy into law. She said he would be granted “perpetual criminal immunity” for ongoing polygamous relationships that began before 2011.

None of the allegations have been proven in court.

Blackmore sat quietly in court Monday morning watching the proceedings. His shock of white hair, neatly combed back, contrasted his sharp black suit. He held a ball cap in his lap bearing the name of his family business: J. R. Blackmore & Sons Ltd.

Arvay told the court that Blackmore’s 25 alleged marriages took place between 1975 and 2001, predating the reference question by a decade.

Arvay also argued that Blackmore’s polygamy charge should be quashed because the government acted improperly by appointing successive prosecutors until it got the recommendation it wanted.

“This is yet another case of, to use the vernacular, ‘shopping’ for a prosecutor to do something the first prosecutor wouldn’t do,” said Arvay.

In 2007, special prosecutor Richard Peck concluded that polygamy was the root cause of Bountiful’s alleged issues. But rather than recommend charges he suggested a constitutional question be referred to the courts to provide more legal clarity.

Instead, the province opted to appoint a succession of other prosecutors until one eventually recommended taking legal action in 2009.

Those charges were thrown out later that year, after Arvay successfully argued the province had acted inappropriately by giving the new prosecutor an identical mandate to the first. It was only then that the province posed a reference question to the B.C. Supreme Court on the constitutionality of polygamy.

Horsman argued that circumstances had changed enough since Peck’s recommendations to warrant the appointment of special prosecutor Peter Wilson in 2012.

In addition to the earlier reference question clearing up the legal grey area, Horsman said new evidence had come to light when American police seized records from a fundamentalist ranch in Texas. She said the 2008 investigation revealed girls were allegedly being moved across the border between polygamous communities.

B.C. Supreme Court Justice Austin Cullen reserved his judgment.

— Follow @gwomand on Twitter

Geordon Omand, The Canadian Press