Columbia -- Midlands political and business leaders intensified their effort Monday to revive a sales-tax collection exemption that Amazon wants to open a distribution center near Cayce.

Backers are lining up a blitz of endorsements from business groups and elected leaders, including U.S. Rep. Joe Wilson, a Republican from Springdale. Their message: The promise of 1,249 new jobs should override complaints that the tax break is unfair to other merchants.

The state House could vote again on a five-year exemption from collecting taxes on sales to S.C. residents as early as Wednesday. The House rejected the incentive 71-47 on April 27.

"It's still a long shot, but there's a pulse that's growing stronger," said Randy Halfacre, Lexington mayor and president of the Greater Lexington Chamber of Commerce. If we fail to do this, we lose a tremendous opportunity."

House Republican leader Kenny Bingham, R-Lexington, said comfort with the proposal in the Legislature is increasing but called its fate uncertain.

Meanwhile, a coalition of local merchants and national chains fired a new barrage of radio ads attacking the proposal as a sweetheart deal for the online retailer.

"They want to provide those jobs by giving Amazon a special deal that's unfair to everybody else," said Brian Flynn, executive director of the S.C. Alliance for Main Street Fairness. His organization is bankrolled by national retailers -- including Wal-Mart, Target, Best Buy and Lowe's -- who say the proposal would give Amazon too much of an advantage.

The tax break also is under fire from Tea Party Republicans as a giveaway.

"This is a perfect opportunity to say it is not business as usual and the era of corporate welfare and special interest is coming to an end," Allen Olson of Irmo, chairman of the Columbia chapter of the Tea Party, said in a letter to local officials.

Amazon seeks temporary sales-tax exemptions in other areas when it plans to open facilities. Shoppers perceive Amazon's prices as cheaper because of the lack of taxes, other retailers say. Those buyers are required to pay taxes on purchases from Amazon, but few do, state revenue officials say.