Attleboro area communities would lose almost $19 million in annual revenue within two years if voters approve Question 1 on the Nov. 4 ballot.

That estimate comes from the Massachusetts Taxpayers Foundation, a non-partisan organization funded by business, which is fighting the referendum to eliminate the state's income tax by 2010.

The income tax accounts for 40 percent of the state's revenue. However, the organization says, the state spends a large portion of its $28 billion budget on non-discretionary items. These include such costly expenses as federal requirements for Medicaid and constitutionally-mandated education aid to local schools.

As a result, the organization estimates that all other budgets would have to be reduced by 71.1 percent by 2010, when the phase-in of the income tax elimination would be complete.

The organization then estimated what a 71.1 percent loss in state aid would mean to each of the state's 351 cities and towns. In the Attleboro area, the total loss in revenue would be $18.9 million annually, according to the organization. Leading the way would be Attleboro, where an almost $5.5 million cut in state aid would represent a more than 5 percent loss in revenue for the city.

"Those kinds of cuts could not be absorbed by the city of Attleboro without devastating effects to services that we provide to the citizens of Attleboro," said Barry LaCasse, the city's director of budget in administration.

The foundation report said no Chapter 70 aid to local schools would be cut because of the state's constitutional requirement.

However, LaCasse said schools still would be affected if Question 1 passes.

"There are other expenses that the city pays for that are not covered under the Chapter 70: transportation, facility maintenance, capital improvements to the schools," he said.

Mayor Kevin Dumas and all area legislators, as well as all candidates for state legislative seats in the area, are opposed to Question 1.

MIKE KIRBY can be reached at 508-236-0344 or at mkirby@thesunchronicle.com.