The British Columbia and federal governments disagreed Tuesday on the exact definition of polygamy, with the province suggesting the law against multiple marriage doesn't apply to women with more than one husband and Ottawa insisting that it does.

The two levels of government each brushed aside the discrepancy, suggesting it makes little difference in assessing whether the law violates the religious freedoms of the polygamous community in Bountiful, B.C.

But the inconsistency demonstrates the delicate task before the court as it spends the next two months considering whether it's constitutional to prohibit polygamy. The unsuccessful prosecution of two leaders in Bountiful last year prompted the province to ask for the court's opinion.

Craig Jones, the lawyer for the B.C. government, argued the law was only ever meant to target men with multiple wives, the most common form of polygamy known as polygany.

All of the problems associated with polygamy -- including child brides and the discrimination of women -- are the direct result of allowing men to marry multiple women, said Jones.

"It was clear what behaviour they (Parliament) wanted to address," he said. "All of the harms we are going to be demonstrating are specific to polygany."

Jones said instances of women with multiple husbands, known as polyandry, are incredibly rare. And he said neither polyandry nor same-sex, multi-partner relationships bring about the same harms to the people involved and to society as a whole as polygany.

"It is arguable that Parliament could not criminalize polyandry and same-sex, multi-partner conjugality even if it wished to," said Jones.

"Polyandry does carry some risk of harms that might be associated with it, but evidence for these is speculative and weak. ... The fact is that the overwhelming majority of polygamy in practice is traditional, usually religious, patriarchal polygany."

He added that when Parliament brought in the polygamy laws in 1890, the government of the day was clearly concerned about multiple wives in some cultures -- namely Mormons, Muslims and First Nations.

Jones made the point as he rejected a criticism made by some opponents of the law: that the crime of polygamy sweeps in relationships that aren't harmful.

The federal government's lawyer agreed the law was primarily intended to target men with multiple wives, as in Bountiful, but she rejected the suggestion the law only covers that scenario.

"We do not say that polygamy should be read as exclusively polygany," said Deborah Strachan. "However, we certainly concede that the concern of the legislators and the purpose of this provision had to do with the harms associated with polygany."

Critics of the law plan to point to that discrepancy as proof the Criminal Code section banning multiple marriages is vague and overly broad.

But Strachan argued the disagreement is largely insignificant.

"What the court has is a different approach to interpretation," she said. "When the respective interpretations are analysed, I expect the court will find that they both cover essentially the same conduct."

The provincial government's lawyer also defended the law against complaints that it infringes on religious freedoms or was originally intended to persecute Mormons and impose Christian values onto society.

Jones said Parliament was interested in protecting society from the harms associated with polygamy, which he said are the inevitable result in a society that allows men to marry multiple wives.

"If it were simple prudishness motivating the ban, then why should it not include orgies, which would have been no less an affront to Victorian sensibilities?" said Jones.

"In the attorney's view, it is because there are harms associated with polygamous marriage that simply do not arise from non-conjugal, multi-partner sex. It is the conjugality . . . that is the heart of the problem."

The constitutional reference case is scheduled to last until the end of January, hearing evidence from more than 30 witnesses including academics, current and former residents of Bountiful, and people living in multi-partner relationships outside of a religion.

The results aren't technically binding, but experts have said other courts would certainly look to the decision for guidance and the case is expected to ultimately end up before the Supreme Court of Canada.

There are also about a dozen interveners, including religious groups, women's rights organizations and civil liberties advocates.

Oler, who leads a faction within Bountiful connected to the U.S.-based Fundamentalist Church of Jesus Christ of Latter Day Saints, or FLDS, is also an intervener, while Blackmore and his congregation are boycotting the hearings.

The mainstream Mormon church renounced polygamy about a century ago.