Google Vice President of Commerce Stephanie Tilenius speaks during the Google Wallet launch event on May 26, 2011, in New York. (Mary Altaffer/AP)

Verizon is denying that it’s “blocking” the app, however, and said that it is in “commercial discussions” with Google on the matter.

In a statement, Verizon spokesman Jeffrey Nelson said that Google Wallet requires different considerations because it’s simply different from other apps.

“Google Wallet does not simply access the operating system and basic hardware of our phones like thousands of other applications,” Nelson said in a statement. “Instead, in order to work as architected by Google, Google Wallet needs to be integrated into a new, secure and proprietary hardware element in our phones.”

Others, however, say that Verizon isn’t supporting Google Wallet on the Galaxy Nexus because the company is working with AT&T and T-Mobile on its own contactless payment service, ISIS.

Media reform group Free Press said Tuesday that Verizon’s decision is hurting consumers, competition and innovation, and illustrates a need for stronger consumer protections from the Federal Communications Commission.

“Verizon should stop pressuring third parties, including its own business partners, into removing competing applications from consumers’ hands,” a Free Press statement said.

Those sentiments were echoed by the consumer advocacy group Public Knowledge. In a statement, Public Knowledge’s Howard Feld said, “Today’s dispute between Google and Verizon is just the type of situation that likely would not happen if it were clear that a firm ‘no discrimination’ standard were in effect for wireless services.”

Sprint was the only wireless carrier partner at launch. The only phone capable of using Google Wallet at that time was the Sprint and Google co-branded Nexus S. Other launch partners included MasterCard and Citibank. Visa and American Express now support Google Wallet as well. But Google hasn’t announced support from the other national wireless carriers, which have all invested heavily in ISIS.

ISIS, meanwhile, has gathered the support of handset makers including HTC, LG, Motorola, Research in Motion, Samsung, and Sony Ericsson.