A Massachusetts Superior Court Judge ordered Cambridge on Thursday to stop paying insurance benefits to domestic partners of city workers, in a decision that opponents of gay marriage claim as another victory in their Massachusetts campaign.

Middlesex Superior Court Judge James F. McHugh ordered Cambridge, the first city in Massachusetts to offer benefits to couples in domestic partnerships, to stop paying the benefits by the end of next January.

According to the ruling, 71 people will lose health insurance benefits worth about $2,790 a year. While anyone can apply for domestic partnership benefits, all but two of those who are currently registered to receive them are gay, according to Cambridge officials.

The American Center for Law and Justice (ACLJ) filed the suit against Cambridge last March, after a similar suit shut down Boston's domestic partnership program last July. The ACLJ is a conservative Virginia group that opposes abortion and gay marriage and champions school prayer.

Vincent McCarthy, who argued the case and is the ACLJ's senior northeast counsel, said the ruling foiled an unconstitutional and illegal ordinance.

"The Cambridge ordinance is simply an attempt to circumvent state marriage laws," he said. "It's clearly just trying to set up a gay parallel marriage."

The ordinance, passed unanimously in 1992, let unmarried couples of any sexual orientation register with the city to gain hospital visitation rights, access to their partner's children's school records, as well as municipal health insurance benefits for partners of city workers or teachers.

The ruling surprised few on either side of the issue, since the Massachusetts Supreme Judicial Court overturned Boston's domestic partnerships benefits program, saying they conflicted with a 1955 state law that limits benefits to worker's spouses and children.