French President Francois Hollande has signed the country's controversial gay marriage bill into law.

The constitutional council yesterday rejected a challenge by conservative politicians, saying the law was constitutional.

The first marriage under the law is due to be held in Montpellier in southern France on 29 May.

France's parliament passed the law legalising gay marriage last month after a national debate, which also saw violent protests in a number of cities.

The law was one of Mr Hollande's pre-election promises and sees France become the 14th country to legalise gay marriage.

It follows 13 others including Canada, Denmark, Sweden and most recently Uruguay and New Zealand in allowing gay and lesbian couples to wed.

In the US, Washington DC and 12 states have legalised same-sex marriage.

Groups opposed to gay marriage plan to stage another large protest on 26 May