A judge in British Columbia has ruled that Canada's polygamy laws are constitutional, rejecting the argument from two B.C. polygamists who claimed the law violated their charter rights.

Winston Blackmore and James Oler were found guilty of having multiple wives in B.C. Supreme Court last July. They returned to court to argue their convictions were null because the law itself was unconstitutional under the Charter of Rights and Freedoms.

On Friday, B.C. Supreme Court Justice Sheri Ann Donegan rejected the argument, stating that Blackmore and Oler considered their lifestyles above the law when they continued to marry women in Bountiful, B.C.

Blackmore and Oler showed little emotion as the judgment was read. About a dozen of Blackmore's daughters were in attendance in the Cranbrook courtroom.

Experts say the B.C. Supreme Court ruling against the former bishops of Bountiful, B.C., could have wider legal implications 2:18

Both men are former bishops in the small fundamentalist Mormon community located in southeastern B.C. They argue that polygamy law infringes on their charter rights to freedom of religion and expression.

Neither denied having multiple marriages. Blackmore was found to have married more than two dozen women, while Oler had five wives. Blackmore has fathered more than 145 children from his marriages.

"I'm guilty of living my religion and that's all I'm saying today because I've never denied that," Blackmore told reporters after the last year's guilty verdict.

Both men are the first in modern Canadian history to be convicted of polygamy. They will now be sentenced barring further appeals, although there is no precedent in Canadian law.

Winston Blackmore, a religious leader of the polygamous community of Bountiful, located near Creston, B.C., shares a laugh with six of his daughters and some of his grandchildren in 2008. (Jonathan Hayward/Canadian Press)

Last year, court heard Bountiful residents are members of the Fundamentalist Church of Jesus Christ of Latter-day Saints, which condones plural marriage.

In December, Blackmore argued that he believed he was allowed to practise polygamy because he wasn't charged when police investigated allegations about his multiple wives in the 1990s.

Winston Blackmore leaves the Bountiful community centre in 2013. (Jonathan Hayward/Canadian Press)

His lawyer, Blaire Suffredine, argued that the unions were never legal marriages, but common-law relationships sanctioned by Blackmore's church, and carry no legal weight.

Special prosecutor Peter Wilson argued Blackmore was always at risk of prosecution, even though Canada's polygamy laws have in the past been constitutionally vague.

Wilson said the B.C. Supreme Court has already ruled that it is not unconstitutional to charge someone with polygamy, as noted in a 2011 reference case.