Republican attorneys general from three states this week filed a lawsuit that seeks to prevent the addition of the Equal Rights Amendment (ERA) — which would prevent sex-based discrimination — into the Constitution.

The suit by the lawyers from Alabama, South Dakota and Louisiana comes as Virginia appears poised to ratify the amendment, which could push it over the three-fourths of states threshold necessary for it to become part of the Constitution.

Legal questions have remained about whether Virginia’s likely ratification would result in a constitutional amendment. When the amendment was passed by Congress in 1972, it was given a seven year ratification deadline that was later extended to 1982.