National Harbor casino advocates tally lost gaming dollars Developer Milton V. Peterson stands at the site where he wants to build a high-end casino at National Harbor. (Photo by Astrid Riecken for The Washington Post) A labor-led group aligned with National Harbor developer Milton V. Peterson is continuing to pull out all the stops to convince Maryland lawmakers to allow a casino in Prince George's County. The latest: a new Web site featuring a continuously updated, national-debt-style clock that purportedly shows how much tax revenue is being lost each second the legislature waits to pass an expanded gambling plan. The site, authorized by the Building Trades for National Harbor, also includes two other clocks. One shows money the state is losing while continuing its practice of buying or leasing slot machines for casino owners, rather than having the owners do that themselves, as is the case in most states. A shift in that responsibility was among the recommendations of a work group launched by Gov. Martin O'Malley (D) that also weighed the merits of a Prince George's County casino. The third clock shows money leaving the state as gamblers continue to travel to casinos in West Virginia, Delaware and Pennsylvania, all of which have table games, unlike Maryland's three open slots facilities. The labor-led group is also airing pro-National Harbor television and radio ads and coordinating phone calls to lawmakers. The numbers on its Web site are certain to be disputed by the Cordish Cos., the developer of Maryland Live! casino in Anne Arundel County and the most vocal opponent of a new site in neighboring Prince George's. In filings with O'Malley's work group, Cordish contended the state could actually lose tax revenue under a plan that included a Prince George's casino. That's in part because the state does not have enough gamblers to sustain a new facility, the company argued. Cordish instead suggested what it dubbed a sure bet to generate more revenue for the state: allowing table games at Maryland's five previously authorized slots sites (two of those have yet to open). The coming weeks will be crucial in the debate. O'Malley continues to weigh whether to call a special session on expanded gambling. His work group recommended against that, because three members - all from the House of Delegates - withheld their support from a proposed plan. The plan included authorizing a Prince George's casino, pending voter approval in November. The five O'Malley appointees and three senators on the 11-member panel all endorsed the plan.