PORTLAND – Organized labor is willing to throw its support behind development of a $650 million casino in York County if casino owners reach an agreement with trade unions.

The executive board of the Maine AFL-CIO voted recently to back the casino campaign by the Passamaquoddy and Penobscot tribes if there is a so-called preproject agreement with the unions.

Such an arrangement could benefit casino backers who are putting the casino to a statewide vote in November.

The Maine AFL-CIO has about 60,000 members, and the member unions are politically savvy, especially on economic initiatives, said John Hanson, director of the Bureau of Labor Education at the University of Maine.

“Even though the percent of the total work force that’s unionized is comparatively small, the fact is they’re very familiar with the political process and [are] able to organize and rally their membership,” he said.

The Passamaquoddy and Penobscot tribes, which want to build the casino, haven’t committed to using union labor in either the construction or the operation of the casino and resort they hope to build, nor has Marnell Corrao, the Las Vegas casino developer bankrolling the referendum campaign.

Jim Carson, a member of the executive board and president of the Teamsters Local 340 chapter, said it could help union members if the casino owners reach a preproject approval.

“This would mean several thousand construction jobs for several years, $650 million worth,” he said.

Hanson said union members who lost paper mill and factory jobs are looking for replacement jobs with similar benefits, he said.

The AFL-CIO also is looking for opportunities for members who were working on the Big Dig in Boston but need new jobs now that the project is winding down, Hanson said.

Other large projects in Maine have been built with project labor agreements. They include the Bath Iron Works expansion, Portland pipeline project, and Androscoggin Cogeneration plant.

But some view the agreements as anti-choice and unfairly beneficial to companies with union shops.

Although project labor agreements do not keep nonunion contractors from working on projects, they do require all companies to comply with the terms of the agreement, said Scott Tompkins of the Associated Constructors of Maine.

“You would have to change your company posture to work on the project and meet stringent requirements that typically only union companies can meet,” he said.

The group Casinos No! is concerned that a unionized work force at a casino and its hotel and restaurants could force other tourist attractions out of business by monopolizing the labor pool.

“A lot of people will have to close their doors because they can’t compete against subsidized jobs,” said group spokesman Dennis Bailey.

Christopher St. John, director of the Maine Center for Economic Policy, said business owners might not be happy with unionized jobs at a nearby casino, but area workers could benefit.

“We would expect higher wages generally for occupations like waiters and cooks and dishwashers and chambermaids, occupations like that,” he said.