Boston ? With the nation watching, a weary Massachusetts Legislature suspended debate on a proposed gay marriage ban Thursday after two days of tense negotiations, the slim defeat of three amendments and an angry late-evening walkout by dozens of lawmakers chanting “We want a vote.”

The constitutional convention will resume March 11 when lawmakers will again grapple with the divisive issue that has placed Massachusetts in the national spotlight. Under a ruling by the state’s highest court issued in November, the nation’s first state-sanctioned gay marriages are scheduled to begin taking place across the state in mid-May.

“It has been a struggle for the members, as it is for every citizen,” said House Speaker Thomas Finneran, a Democrat and an ardent opponent of gay marriage. “No one should expect that decisions of this magnitude would be made casually or quickly. Our efforts will continue.”

The adjournment was seen as a victory for gay-rights advocates, who stood vigil outside the House chamber for hours, singing and cheering. They continued to sing “God Bless America” and cheered vigorously when the convention recessed without a vote. During the day, their renditions of the national anthem and chants of “Justice now” could be heard by lawmakers inside.

The decision to adjourn at midnight came after more than 17 hours of debate and negotiations over two days that saw three attempts to ban gay marriage voted down.

Debate was suspended amid discussion of a fourth attempt at compromise — a measure sponsored by bipartisan House and Senate leaders that would have banned gay marriage but adopted civil unions similar to those in Vermont.