Vonage Canada, a leading provider of internet telephones, wants federal regulators to investigate what it calls a "thinly veiled VoIP tax" by one of its competitors.

Joe Parent, vice-president of marketing for Vonage Canada, said Tuesday that Shaw Communications was using the so-called tax to unfairly drive up VoIP prices in Western Canada.

He filed a request to the CRTC asking for an investigation.

"Shaw's VoIP tax is an unfair attempt to drive up the price of competing VoIP services to protect its own high-priced service," Parent claimed, adding that Shaw charges a fee whenever Vonage customers route their calls over Shaw's internet lines.

The case is one part of a growing battle across North America between internet providers and their users.

Internet companies such as Shaw want to charge extra fees whenever people use their lines. The users naturally disagree, saying they already support the internet providers through their monthly bills.

Much of the controversy is around VoIP calls, an acronym for Voice over Internet Protocol, a system whereby telephone calls are routed through a computer internet service instead of the usual telephone system.

Long-distance calls are considerably cheaper because the user does not have to pay telephone charges.

In his announcement Tuesday, Parent said Shaw wants its high-speed internet customers to pay a $10 "quality of service enhancement" fee if they use a VoIP phone service from a provider such as Vonage Canada. He said Shaw argues that its fee is necessary to maintain the quality of independent VoIP services.

Shaw did not immediately return a telephone call to its head office in Calgary.