RICHMOND — Virginia lawmakers are dueling over whether to allow a vote next week on the federal Equal Rights Amendment, with proponents hurling a virtual Hail Mary pass in an effort to make Virginia the 38th — and theoretically last — state needed to ratify the nearly­ ­century-old measure.

Virginia ERA advocates want to bring the amendment to the House floor, where they believe it has enough votes to pass. It already passed the state Senate, as it has multiple times before, but this year it failed again to clear a House subcommittee, never getting a hearing in a full committee.

More than 100 supporters staged a rally Thursday morning on the Capitol steps, chanting “Let us vote” as well as the office phone number for House Speaker Kirk Cox (R-Colonial Heights), who advocates hope could have some influence.

Legislators and ERA supporters took turns at the microphone, pointing to the history of their activism on the issue since before the amendment was ratified by Congress in 1971 and sent to the states. Several recalled demonstrating as children; Del. Kathleen J. Murphy (D-Fairfax) said she watched the ERA’s 1971 passage from the visitors gallery at the U.S. Capitol. All said that they could not believe they were still working on the ERA’s passage 47 years later.

The chants echoed off the federal courthouse, state government offices and lobbyists’ warrens, where the amendment, if successful, will be examined, deconstructed and parsed. Their signs were both forward-looking (“Equality will cure what ails you, Virginia”) and threatening (“Kill the ERA, lose your seat”). After the hour-long rally ended, demonstrators decamped to the legislative office building to lobby in the halls.

On Wednesday night, Del. Hala S. Ayala (D-Prince William) sought to jump-start the stalled amendment by filing a motion to bypass the rules that normally prevent a defeated proposal from being heard before the full House.

Before the ink was dry on her motion, Del. Todd Gilbert (R-Shenandoah) filed a blocking resolution, requiring motions such as hers to get a two-thirds vote instead of a simple majority.

“I think that was a way to put me in my place,” Ayala said. “I did everything according to the rules. . . . These are the same tactics they always use.”

That did not sit well with Gilbert, the House majority leader.

“I’m not sure why my colleague would want to assign such disrespectful intentions to me,” he said. “The only things being disrespected are the purpose, protocol and precedent of the House rules, which have never before been hijacked to advance a particular piece of legislation.”

A third resolution, filed Wednesday night by Del. Marcus B. Simon (D-Fairfax), sought to plug a hole in the rules over which Ayala and Gilbert are battling. Simon’s proposal would allow resolutions, and bills, to be “discharged” from a committee and brought to the floor. “We’re not going to let anyone hide behind the subcommittee system,” he told rallygoers Thursday.

There is a five-day waiting period before House members can decide whether to take up these measures, so it will not come up for a vote until Wednesday, three days before the session is scheduled to end. Its proponents, mostly Democrats, say there are a number of Republicans who want to vote for the amendment but are reluctant to speak out.

Even if the ERA clears those hurdles and passes the General Assembly, the fact that Virginia becomes the 38th state to ratify the federal amendment does not necessarily mean the ERA will become part of the U.S. Constitution.

Congress set a 1979 deadline on its ratification by the states and then extended it until 1982. It was three states short until two years ago, when it was ratified by the Nevada legislature, followed by the Illinois legislature. Congressional proponents have introduced bills to remove the deadline or to start the state ratification process over.

Five states that ratified the amendment later rescinded their votes, but no court has ruled on whether that is allowed.