Brick-and-mortar retailers like Wal-Mart Stores Inc. see an opportunity to claim victory in a lobbying duel against online companies that don't collect sales tax from their customers.

Retailers are urging U.S. senators to take a non-binding vote this week to demonstrate support for allowing states to impose sales taxes on out-of-state online sellers. Opponents including EBay Inc. have prevented House or Senate action so far in a decade-long dispute.

"If this gets 60 votes in the Senate, it's a pretty impressive sign," said Jason Brewer, vice president for communications and advocacy at the Retail Industry Leaders Association, a group based in Arlington, Virginia, that represents companies such as Target Corp. and Dollar General Corp. "Just take a look at the political landscape. How many issues are attracting bipartisan support these days?"