Gay marriage across the world

As Britain's parliament votes on whether to pass legislation to allow homosexual couples to marry following is a breakdown of countries with similar laws on the books.

Gay couples in Britain have had the right to enter into a civil partnership and adopt children since 2005.

- NETHERLANDS: On April 1, 2001 the Netherlands became the first country in the world to legalise same-sex marriage, with the same rights as heterosexuals. Includes the right to adoption.

- BELGIUM: Homosexual couples in Belgium have almost the same rights as heterosexuals. They won the right to marry in 2003 and in 2006 parliament voted into law a bill allowing homosexual couples to adopt children.

- SPAIN: In 2005 Spain became the third member of the European Union to pass a law allowing same-sex marriages. Gay couples can adopt children, whether they are married or not.

- CANADA: Canada adopted a national law allowing gays to marry and adopt in July 2005 though most provinces had already allowed same-sex unions before that date.

- SOUTH AFRICA: The country legalised same-sex unions and adoptions by gay couples in November 2006, becoming the first African nation to do so.

- NORWAY: A 2009 law allowed homosexuals to marry and adopt children. Civil partnerships have existed in the country for 20 years.

- SWEDEN: Homosexuals were allowed to enter into civil partnerships in 1995, and in May 2009 they were given the right to wed in civilian or religious ceremonies on a par with heterosexuals. Since 2003 they have been able to adopt children.

- PORTUGAL: Under a 2010 law Portugal legalised gay marriage, while excluding the right to adoption.

- ICELAND: Prime Minister Johanna Sigurdardottir married her long-time partner in June 2010 as a new law legalising homosexual marriages came into force. Same sex couples who have lived together for at least five years have had the right to adopt children since 2006.

- FRANCE: Lawmakers on Saturday approved a key piece of legislation that will allow homosexual couples to marry and adopt children. A final vote is set for February 12. Since 1999, homosexual couples have had the right to enter civil partnerships.

- ARGENTINA: Gays in Argentina became the first on the South American continent to be able to wed and adopt, after legislation passed on July 14, 2010.

- UNITED STATES: Gay couples can marry in nine US states, as well as in the capital Washington, while Mexico allows unions in Mexico City.

A number of other countries have adopted laws that recognise civil partnerships and give couples more or less the same rights as heterosexuals. Denmark became in 1989 the first nation in the world to recognise civil unions.

Germany followed suit in 2001, followed by Finland (2002), New Zealand (2004), the Czech Republic (2006), Switzerland (2007) and Uruguay, Colombia and Ireland all in 2011. In Australia, five states recognise civil unions between gays, but the federal government does not.