7-Eleven says it will deliver 1.66 million customer signatures to Capitol Hill Wednesday afternoon, wrapping up a summer petition drive that pushed customers to take a stand against credit card interchange fees.

The petition calls on Congress to help lower the amount merchants pay to credit card companies when customers use plastic. The store's effort, and bills in each chamber that address the interchange, are described here in this National Journal story.(subscription).

7-Eleven plans to unveil 130 boxes containing 14,000 petition pads, store officials said. MasterCard is already playing defense. It held its own unveiling yesterday, officially releasing the results of an online survey it conducted in August which questions the validity of 7-Eleven's petition drive.

On a call with reporters yesterday, Shawn Miles, the global head of public policy for MasterCard Worldwide, critiqued interchange fee legislation currently in Congress and said "consumers were ill-advised about what" 7-Eleven's petition drive actually addressed. More on that argument from National Journal:

MasterCard commissioned a study looking at whether the company's petition puts one over on consumers. According to MasterCard's findings, "After reading the 7-Eleven petition, two in three Americans mistakenly believed that consumers would directly and immediately benefit from a reduction in merchant service fees, as it would lead to lower fees on their own credit cards or lower retail prices."