France's constitutional authority on Friday upheld the country's ban on gay marriage, the AP reported.

The law had been challenged by a lesbian couple who have been living in a PACS, or civil partnership, for 10 years. Corrine Cestino and Sophie Hasslauer have been together 15 years and are raising four children.

The Constitutional Council said the ban did not violate the country's constitution, but added that it is up to the country's parliament to make laws.

France, the UK and Germany are among Europe's most powerful – and in many ways liberal – nations yet to adopt gay marriage. All three countries offer gay couples civil partnerships. But France's 1999 law confers fewer rights than marriage.

“Marriage is the only solution in terms of protecting our children, sharing parental authority, settling inheritance problems and eventual custody if one of us were to die,” the couple told AFP news agency.

A recent TNS Sofres poll showed a majority (58%) of respondents favor the legalization of gay marriage, up six percentage points since 2006.

Speaking on LCI television before the verdict was announced, Henri Guiano, an adviser to President Nicolas Sarkzoy, suggested the issue wasn't about to be addressed anytime soon.

“This is a question of society, of civilization even,” he said. “This is a matter that could maybe be broached during the presidential election campaign, by parliamentary debate, but not just for the law.”

Singer Sir Elton John in 2008 said he was happy with his 2005 UK civil partnership to filmmaker David Furnish. After the birth of his son Zachary on Christmas Day, Sir Elton began singing a new tune and now says he would like to be married.