(Robert F. Bukatay/AP)

The move could complicate efforts to craft a bill that has a chance of passing the House of Delegates in a session Gov. Martin O’Malley (D) has advertised for the week of July 9.

A Senate bill died in the House on the final night of the regular session that called for a statewide vote on allowing a full-fledged casino in Prince George’s County and Las Vegas-style table games at Maryland’s five existing slots locations.

The issue remains divisive among Democrats, and House leaders have suggested that a bill could be difficult to pass in the chamber without some Republican support. Similar bills have passed by lopsided margins in the Senate with bipartisan backing.

Last week, O’Malley and the two presiding officers of the legislature announced the membership of a work group to take a closer look at the issue. O’Malley said that he would call lawmakers back into session in July if that group, which has its first scheduled meeting next week, can reach a consensus over a plan.

A key issue is how to compensate other casino owners for additional competition in Prince George’s.

“It is our view that special sessions should only be called in times of true, rather than contrived, crisis,” said a letter released Thursday by House Minority Leader Anthony J. O’Donnell (R-Calvert) and House Minority Whip Jeannie Haddaway-Riccio. “No matter where one stands on the issue, the question of whether or not to expand gaming in Maryland deserved a full and thoughtful vetting through the regular legislative process.”