Boston ? The same court that made Massachusetts the first state to legalize same-sex marriage ruled Monday that a proposal for a constitutional amendment that could ban future gay marriages can move forward.

The ruling came on a lawsuit brought by gay-rights supporters who argued that Atty. Gen. Tom Reilly was wrong to certify the question because the state’s constitution bars any citizen-initiated amendment that seeks to reverse a judicial ruling.

The Supreme Judicial Court rejected that argument, paving the way for the state Legislature to take up the question during a constitutional convention Wednesday. The question would have to be approved by two consecutive legislative sessions before it could be placed on the 2008 ballot.

The same court, in a landmark 2003 ruling, cleared the way for same-sex marriages to begin in Massachusetts in May 2004. More than 8,000 gay and lesbian couples have married.