AUGUSTA – Larry Benoit, a consultant and former aide to Gov. John Baldacci, will run the campaign against the November ballot question to place a cap on property taxes.

Benoit has been hired by a still-evolving coalition that includes the Maine Municipal Association, the Maine Education Association, the Maine State Employees Association, the Maine AFL-CIO and Verizon.

Benoit said the coalition’s political action committee probably will register with the state within a few days.

He said more organizations and businesses, including the Maine State Chamber of Commerce, are likely to join the coalition as the Nov. 2 referendum approaches.

The chamber’s president, Dana Connors, worked with Benoit last fall and again this spring on referendum campaigns dealing with tax relief. Connors said Wednesday the chamber is studying the impact of the tax cap and has not yet decided whether to participate in the campaign.

Benoit served as Baldacci’s chief of staff when the governor was in Congress and worked behind the scenes on Baldacci’s 2002 gubernatorial campaign. Baldacci is not part of the new coalition but will play a major role in the opposition campaign, according to his spokesman, Lee Umphrey.

Referendum supporters have registered four political action committees: the Maine Taxpayer Action Network, which is sponsoring the referendum; Tax Cap Yes!, which is led by former state Sen. Phil Harriman and businessman Eric Cianchette; a group calling itself Tax Cap Now; and the Yarmouth Taxpayers Association.

Both sides in the tax cap battle foresee a costly race.

Kay Rand, Benoit’s partner in the BSSN Resources consulting firm, forecast Wednesday that each side will spend more than $1 million. Harriman forecast that opponents will spend much more than that and that his side hopes to raise $1 million to $1.5 million.

Rand questioned whether opponents will greatly outspend supporters. Noting that this is the third statewide tax-related referendum since 2003, she said prospective contributors’ wallets may be getting a bit thin.