The federal government is considering changes to the law that will make it easier for foreign same-sex couples who married in Canada to obtain divorces, Justice Minister Rob Nicholson said Thursday.

Nicholson also stressed the government has no intention of reopening the same-sex marriage debate after a day of confusion over the validity of marriage licences issued in Canada to same-sex couples from abroad.

Ottawa was pressed to clarify its position on gay marriage after an apparent about-face on the issue surfaced in a Toronto divorce case.

A lesbian couple who married in Canada seven years ago and recently filed for divorce was told by a Department of Justice lawyer that their marriage was not legal.

The stated reason was that because the partners live in Florida and England, where same-sex marriage remains illegal, their Canadian union was invalid too.

The case threw into question thousands of marriages non-residents entered into since 2004, when same-sex marriage became legal in Canada under a Liberal government.

In a statement, Nicholson said the issue centres on dissolution of marriages performed in Canada.

Non-resident couples who marry here must live in Canada for one year before they can legally divorce. The lesbian couple at the centre of the controversy has launched a constitutional challenge of that provision in the Ontario Superior Court of Justice.

Nicholson said he will be "looking at options to clarify the law so that marriages performed in Canada can be undone in Canada."

In an interview with CTV's Power Play, Nicholson's parliamentary secretary Kerry-Lynne Findlay said the Canadian marriages of non-resident same-sex couples are legal in Canada.

Prime Minister Stephen Harper had little to say Thursday other than relate his government's reluctance to wade back into a same-sex marriage debate.

"We have no intention further of opening or reopening this issue," Harper told reporters gathered for a shipbuilding agreement announcement in Halifax.

"This, I gather, is a case before the courts where Canadian lawyers have taken particular positions based on the law. But I will be asking officials to provide me more details with this particular case."

Opposition parties and critics quickly weighed in on the issue, accusing the prime minister of trying to rewrite Canada's same-sex marriage laws "in stealth."

In a statement, Egale Canada, a human rights organization advocating equality for lesbian, gay, bisexual and transgender communities, called the apparent flip-flop "a direct insult to gays and lesbians both in Canada and abroad."

If the federal lawyer's arguments in the Toronto divorce case are a misunderstanding, Harper should make that clear, NDP MP Olivia Chow said.

With files from Kieron Lang and The Canadian Press