Washington (CNN) - The nation's capital city is expected to take a major step Tuesday towards legalizing same-sex marriage.
The District of Columbia's city council is scheduled to vote - and expected to pass - a measure that would recognize gay marriages as legal. The city council overwhelmingly passed the bill in a previous vote on December 1.
Tuesday's second vote is needed to send the measure to District Mayor Adrian Fenty, who has said he will sign the bill. Then the measure goes to Congress for a 30-day review period, but it's considered unlikely that the Democratic majority on Capitol Hill will block the bill. By law, Congress has the right to review and overturn laws created by the District's city council.
If the measure becomes law, the District would join Massachusetts, Connecticut, Vermont and Iowa in allowing legal same-sex marriages. A law legalizing gay marriage in New Hampshire takes effect on January 1.
Earlier this year, lawmakers in Maine approved a measure legalizing same-sex marriages, but voters in the state last month passed a referendum to overturn the new law. Last week, New York's state senate defeated a bill that would legalize gay marriages. A similar bill stalled last week in New Jersey's state senate.
–CNN Deputy Political Director Paul Steinhauser contributed to this story