The Portuguese parliament has approved at first reading a bill to legalise gay marriage but rejected proposals to allow same-sex couples to adopt.

The vote went mainly on party lines, with the left-wing majority backing the measure proposed by Prime Minister Jóse Sócrates and the right-wing opposition voting against.

It will now be reviewed in committee before coming back for a final vote in parliament.

Mr Sócrates said the aim was to remedy decades of injustice towards gays, recalling that as recently as 1982 homosexuality was a crime in Portugal.

Parliament also defeated a demand backed by the right for a referendum following a petition which collected more than 90,000 signatures.