Gay and lesbian people in the US state of Washington came a step closer to marriage this week, as a new state law granting same-sex couples some of the rights enjoyed by heterosexuals came into effect.

Domestic partnerships give registered partners several of the rights granted to married couples, including the right to visit a partner in hospital, the right to authorise autopsies and organ donations, inheritance rights, and the right to arrange a funeral.

“It’s a significant first step,” Democrat state Senator Ed Murray, Washington’s senior gay lawmaker, told Associated Press.

“But it’s only a first step.”

To qualify, couples have to be at least 18, live together and not already be married or in a domestic partnership with another person.

Last July, Washington state rejected arguments in favour of same-sex marriage.

The state Supreme Court upheld the 1998 Defence of Marriage Act by a 5-4 vote, arguing that it, “preserves the institution of marriage and the healthy families and children it promotes.”

The ruling came 16 months after a case involving 19 gay and lesbian couples challenging the act came under consideration by the Supreme Court.

The couples claimed that the Defence of Marriage Act, which limits marriage to heterosexual couples, violates Washington state’s constitution.

But the court argued that discrimination laws do not entitle same sex couples to marriage and the ban is therefore not unconstitutional.

It added that no court could overturn the Act, leaving the only chance of a gay marriage law in the hands of the Senate or House of Representatives.

Massachusetts remains the only US state to allow same-sex marriage.

From January 2008, in Connecticut, Vermont, New Jersey, California and New Hampshire, same-sex couples will be able to enter legal unions offering all the rights of marriage.