Portugal would become the eighth country in the world to permit gay marriage if parliament, as expected, approves legal changes Friday.

The country's ruling socialist government is scheduled to present a bill removing the stipulation that marriage is strictly between a man and a woman.

The government bill has garnered support of the majority of parliament, although right-wing parties remain opposed.

Paulo Corte-Real, head of a lobby group called Lesbian, Gay, Bisexual and Transsexual Intervention, said it would be a "historic day" for Portgual if the bill goes through.

"It's a milestone in the fight against discrimination," he told The Associated Press on Thursday.

If the proposed law passes, the first state-sanctioned gay marriages could begin in April — one month before Pope Benedict XVI arrives for an official visit.

Gay marriage around the world

Only seven countries now allow gay marriage — Canada, Sweden, Norway, Spain, Belgium, the Netherlands and South Africa.

In the United States, New Hampshire became the sixth state to legalize same-sex marriage in June 2009, joining other states, including Vermont, Massachusetts, Connecticut and Iowa.

Several major cities around the world permit same-sex unions. In 2002, Buenos Aires became the first South American city to legalize it. Four other Argentine cities, Mexico City, and parts of Brazil have followed suit.

Like neighbouring Spain, Portugal is an overwhelmingly Roman Catholic country and previous efforts to introduce gay marriage have run into strong resistance from religious groups and conservative lawmakers.

Last July, Portugal's Constitutional Court upheld the country's ban on gay marriage, rejecting an appeal by two lesbians seeking to wed. It said the constitution, while granting equal rights, did not state that same-sex marriages were permitted.

With files from The Associated Press