The first debate on Cobb County’s proposed sales tax extension was held Wednesday night at the Cobb government building.

The proposal would extend the current one-percent sales tax another four years through 2015.

Supporters maintained the tax would keep millage rates low, improve infrastructure and that 30 percent of the tax would be paid by people outside of the county. Opponents refuted all of those claims and questioned the timing of a tax extension during an economic downturn.

This week SPLOST supporters, Citizens for Cobb’s Future, released a list of area business and civic groups that support the tax extension. SPLOST opponents, led by the Cobb County Taxpayers Association, have scheduled their next “Ax The Tax” rally for March 5 in the Marietta square.

If approved by voters, the tax levy extension would begin Jan. 1, 2012, just as the current six-year SPLOST ends Dec. 31. The new SPLOST is expected to generate $492 million for county and city projects.

Early voting for the March 15 referendum began this week and runs through March 11.