WASHINGTON, United States (AFP) — The acrimonious battle over “net neutrality” in America comes to a head Thursday with a US agency set to vote to roll back rules enacted two years earlier aimed at preventing a “two-speed” internet.

The Federal Communications Commission was expected to narrowly pass the measure to scrap the 2015 neutrality rules, which require internet service providers to treat all online traffic equally without blocking or hampering of rivals.

Backers of the new proposal say it would encourage innovation and investment by removing heavy regulatory burdens. But critics argue it could kill the “open internet” and enable broadband firms to choose what people see or don’t see online.

The rollback is being engineered by FCC chairman Ajit Pai, appointed by President Donald Trump.

As a member of the FCC, Pai was a fierce critic of the neutrality rules adopted in 2015 and earlier this month unveiled his plan named the “Restoring Internet Freedom” order.

Amid a wave of protests from online firms and activists opposing the new plan, Pai said his reforms would usher in a return to a “light-touch regulatory approach” that has allowed the internet to flourish.

The dispute over net neutrality has been the subject of several court battles over the past decade, with backers arguing strong rules are needed to guard against powerful broadband firms like Comcast and AT&T acting as “gatekeepers” that can punish rivals.

Tim Berners-Lee, the British engineer and creator of the World Wide Web, joined other internet pioneers in pleading for neutrality rules to remain.

“Net neutrality — the principle that internet service providers (ISPs) treat all traffic equally — underpins the internet as we know it today,” Berners-Lee wrote on the online platform Medium this week.

If the rules are repealed, Berners-Lee said, “ISPs will have the power to decide which websites you can access and at what speed each will load. In other words, they’ll be able to decide which companies succeed online, which voices are heard   — and which are silenced.”

But Michael Powell, a former FCC chairman who in 2005 evoked the principle of “four internet freedoms” — which some say parallel net neutrality — said activists are stirring a tempest in a teapot.

“New-age Nostradamuses predict the internet will stop working, democracy will collapse, plague will ensue and locusts will cover the land,” Powell said in a guest blog for the website Recode.

“Sadly, rational debate, like Elvis, has left the building.” said Powell, who now heads the lobby group for broadband firms called NCTA – the Internet & Television Association.

Powell maintained that broadband firms “highly value the open internet and the principles of net neutrality, much more than some animated activists would have you think… because it’s a better way of making money than a closed internet.”

Backers of the Pai plan say little will change and that any discriminatory conduct will be dealt with by another agency, the Federal Trade Commission, which enforces consumer protection and antitrust laws.

Still, the debate has hit a feverish pitch, with street protests in many cities and online, where websites ranging from Kickstarter to Pornhub putting up notices warning of the harmful potential from a rollback.

The FCC’s online platform has been caught in the firestorm, with one investigation showing two million of 21 million public comments were sent with stolen identities.

Thirty-nine senators signed a letter urging the FCC to delay the vote, claiming that Pai’s assertion that the plan would “restore” regulations of the past was incorrect.

“Even under the Bush-era FCC, the agency adopted open internet principles,” the letter said. “The future of the internet hangs in the balance.”