A bill that seeks to enshrine the principle that all internet traffic should be treated equally was introduced before the U.S. House of Representatives on Wednesday.

Massachusetts Democratic Representative Edward Markey, chairman of the House energy and commerce committee's subcommittee on telecommunications and the internet, introduced the bill to promote the principle of "net neutrality," arguing it is needed to prevent network providers from shaping traffic on the internet or otherwise favouring one website over another.

"Because of the vital role that broadband networks and the internet fulfill in exercising our First Amendment rights to speak, it is important that the United States adopt a policy endorsing the open nature of broadband networks," said Markey in a statement.

The Internet Freedom Preservation Act, co-sponsored by Republican representative Chip Pickering of Mississippi, requires the Federal Communications Commission to assess whether broadband providers are "blocking, thwarting or unreasonably interfering" with consumers' rights to access, send, receive or offer content.

Markey's legislation is a modified version of a bill he tried to introduce in 2006 that would have penalized ISPs that attempted to block or otherwise shape content. The new bill is different in that it contains guidelines but no new regulations.

"It does, however, suggest that the principles which have guided the internet's development and expansion are highly worthy of retention, and it seeks to enshrine such principles in the law as guide stars for U.S. broadband policy," he said.

Content providers such as Google and Yahoo want to keep net neutrality, arguing that losing it would destroy the open nature of the internet. Google policy analyst Derek Slater, writing in the company's public policy blog on Wednesday, said neutrality is needed to spur innovation.

"Some major broadband service providers have threatened to act as gatekeepers, playing favourites with particular applications or content providers, demonstrating that this threat is all too real," he wrote. "It's no stretch to say that such discriminatory practices could have prevented Google from getting off the ground — and they could prevent the next Google from ever coming to be."

However, telecom companies in Canada and in the U.S. argue controlling data transmissions over the internet would allow them to ensure quality of service and encourage investment in broadband networks.

Net neutrality is not enshrined by law but its principles are supported by some regulations. But in both the United States and Canada internet service providers have been caught engaging in practices that go against the principle.

An Associated Press investigation in October 2007 found that Comcast Corp., the second-largest U.S. internet service provider, was actively interfering with attempts by some of its high-speed subscribers to share files online.

Comcast said in a filing with the FCC on Tuesday that it did block some users, saying a small number of them were hogging too much bandwidth on its broadband network.

A number of Canadian ISPs, including Rogers Communications Inc. and Bell Canada Inc., have also admitted to traffic shaping, but have denied blocking peer-to-peer applications.

Net neutrality hasn't been a priority of Canada's Conservative government.

A Canadian Press report in February citing internal documents suggested the government was reluctant to impose consumer safeguards for the web because it wants to protect the competitive position of businesses that offer internet access.