France's president has signed into law a controversial bill making the country the ninth in Europe, and 14th globally, to legalize gay marriage, BBC News reported.

On Friday, May 17, the Constitutional Council rejected a challenge by the right-wing opposition, clearing the way for Francois Hollande to sign the bill.

He said: "I have taken [the decision]; now it is time to respect the law of the Republic."

The first gay wedding could be held 10 days after the bill's signing. But Parliamentary Relations Minister Alain Vidalies told French TV he expected the first ceremonies to take place "before July 1".

Hollande and his ruling Socialist Party have made the legislation their flagship social reform since being elected a year ago.

After a tortured debate, the same-sex marriage and adoption bill was passed by France's Senate and National Assembly last month.

The bill was quickly challenged on constitutional grounds by the main right-wing opposition UMP party of former president Nicolas Sarkozy.

But the Constitutional Council ruled Friday that same-sex marriage "did not run contrary to any constitutional principles," and that it did not infringe on "basic rights or liberties or national sovereignty".

It said the interest of the child would be paramount in adoption cases, cautioning that legalizing same-sex adoption would not automatically mean the "right to a child".

Scores of protesters took to the streets of Paris to voice their opposition to the ruling on Friday: previous, occasionally violent, demonstrations against the bill have drawn hundreds of thousands onto the streets.

Opinion polls have suggested that around 55-60% of French people support gay marriage, but only about 50% approve of gay adoption.

France is now the 14th country to legalize gay marriage after New Zealand last month.