A former Prince George's County Council chairman has filed a lawsuit over how the results of the Maryland ballot question on expanded gambling will be counted.

Thomas Dernoga, a Democrat who represented the Laurel area for nine years and who filed the suit on behalf of eight plaintiffs who live near the proposed new casino site at National Harbor, is looking to clarify whether the gambling referendum requires a majority of actual voters or registered voters to pass.

According to the 2007 state constitutional amendment that allowed slot machines, "a majority of the qualified voters in the state" is required to expand gambling.

"There's three levels -- there's the number of people voting on the question, there's the number of people voting on Election Day and there's the number of people registered to vote," Dernoga said. "If you have a vote, how do you count it?"

Some voters don't fill out their entire ballot, and if those who skip over gambling expansion are counted against it, the referendum will have a harder time passing. Such was the case in 2010, when a state ballot measure to hold a constitutional convention got the support of 55 percent of voters who answered the question, but only 48 percent of total voters. The measure did not pass.

In 2008, however, those who did not answer the question weren't counted as the ballot referendum on allowing slots passed with 58 percent of the vote. The vote created the constitutional amendment at issue in the lawsuit.

A pair of advice letters from Attorney General Douglas Gansler's office -- one to House Speaker Michael Busch, D-Anne Arundel, in 2011 and another to state Sen. Edward Kasemeyer, D-Baltimore/Howard, in 2007 -- indicate that passing the expansion would require a majority of those who vote on the measure.

"If 'a majority of the qualified voters in the state' is read literally, the result would be to require more votes than likely would be cast in the entire election," the 2007 letter says. "Such a result would be absurd."

The 2011 letter states outright that "a simple majority of the votes cast on the question is all that is necessary to declare the measure passed." This reading of the state Constitution, the letter says, is in line with the General Assembly's intentions in writing the 2007 amendment.

Dernoga opposes gambling in Maryland, but said that the lawsuit was not about making expansion more difficult to pass.

He said the Attorney General's Office was ignoring the "plain language" of the Constitution and making assumptions about lawmakers' intentions.

"This whole thing has been sort of rushed," he said. "The public is entitled to have the Constitution be complied with."

Dernoga said he does not expect to hear back before Election Day but hopes things will move quickly once votes have been counted.

The Attorney General's Office declined to comment on pending litigation.