THE Foreign Affairs Minister, Bob Carr, has become the latest Labor politician to declare his support for same-sex marriage.

Senator Carr, who has not made his position on the issue public until now, said yesterday that his support for gay marriage was consistent with his work as NSW premier to remove from state laws discrimination against gay and lesbian people.

While he respected the views of those who held more conservative opinions on marriage, it ''seemed churlish to deny access to marriage to groups that wanted it'', he said.

The Senate is about to begin debating proposals by four Labor senators to legalise gay marriage. While support for same-sex marriage is stronger in the Senate than in the House of Representatives, campaigners are pessimistic about the bill passing when it goes to a vote this week.