LITTLE ROCK — A ballot committee backed by Oaklawn Park thoroughbred track on Tuesday filed a lawsuit challenging a proposed constitutional amendment that would allow casinos in four counties.

In the suit, the Arkansas Racing Alliance asks the state Supreme Court to declare that professional poker player Nancy Todd’s proposed amendment is invalid and order that no votes cast for it be counted.

If approved by voters, the amendment would permit Nancy Todd’s Poker Palace and Entertainment LLC to operate casinos in Crittenden, Franklin, Miller and Pulaski counties. Secretary of State Mark Martin has ruled the measure legally insufficient but has certified it for the ballot while Todd appeals his ruling to the state Supreme Court.

Martin found that the wording of the measure did not adequately inform voters of the effect the amendment would have on electronic games of skill at Oaklawn and Southland Greyhound Park in West Memphis.

The high court heard oral arguments in Todd’s appeal last week. By Tuesday it had not issued a ruling.

The Arkansas Racing Alliance’s suit alleges that Todd did not submit enough valid signatures to get the measure on the ballot and that the wording of the measure does not adequately describe the proposed amendment.

The group also requested the appointment of a special master in the case and asked to present oral arguments.

The alliance also is an intervenor in Texas businessman Michael Wasserman’s appeal of Martin’s rejection of a separate proposed amendment that would allow Wasserman to operate casinos in seven counties.

Todd did not immediately return a call Tuesday seeking comment.