The sites will display a variety of messages, or simulate the potential effects of losing the basic principle of all internet traffic being treated equally.

The US communications regulator earlier this year voted to remove an Obama-era rule that would prevent the prioritisation - or "throttling" - of data, as well as other measures campaigners consider to be detrimental to the internet.

Opponents to net neutrality say it stifles innovation and discourages investment in telecoms infrastructure.

Among the companies protesting, the headliners include Google, Facebook, Amazon, Reddit, AirBnB, Twitter and Snapchat.

Crowdfunding site Kickstarter will be involved, as will craft-selling site Etsy and dating app OkCupid. PornHub, one of the world's most visited sites, will also be taking part.

"Internet service providers could create special fast lanes for content providers willing to pay more," said Corey Price, vice president of PornHub.

"That means slow streaming, which, especially in regards to online porn, is quite problematic as you can imagine."

Campaigners told the BBC around 80,000 websites and services in all are taking part in the co-ordinated action that is designed to draw attention to a public consultation about the proposed rule reversal.

"What we want the FCC to hear, and we want members of Congress to hear, is that net neutrality is wildly popular, which it is, and we want them to stop trying to murder it," said Sean Vitka, a lawyer for pro-net neutrality groups Demand Progress and Fight for the Future.

"It stops large companies, like internet service providers, from controlling who wins or loses on the internet. There'd be nothing to stop your ISP stopping the next Facebook, the next Google, from accessing customers equally.

"If a new company can't access companies on the same terms as the incumbents they're not going to have the chance to thrive."

This kind of protest technique has been effective in the past.

When numerous firms went "dark" in opposition to the Stop Online Piracy Act, which they argued was a threat to free speech, it led to the bill being withdrawn.

But protest groups face a tougher battle in convincing the Republican-controlled FCC headed by new commissioner Ajit Pai.

Earlier this year the department described President Obama's rule as risking "online investment and innovation, threatening the very open internet it purported to preserve".

It added: "Requiring ISPs to divert resources to comply with unnecessary and broad new regulatory requirements threatens to take away from their ability to make investments that benefit consumers."

Promoting investment in infrastructure is the strongest of the anti-net neutrality arguments, with major telecoms companies arguing that the Googles and Facebooks of the world would not be able to run were it not for the high-speed internet connections offered by internet service providers.

Campaigners have countered this by suggesting it is the lure of enticing premium services like Netflix that tempt users into paying more for better internet access.

AT&T role

A more curious position came from mobile carrier AT&T which said it was supporting the protest - despite in the past being a vocal opponent of net neutrality.

"We agree that no company should be allowed to block content or throttle the download speeds of content in a discriminatory manner," the firm said.

"So, we are joining this effort because it's consistent with AT&T's proud history of championing our customers' right to an open internet and access to the internet content, applications, and devices of their choosing."

Campaign groups gave the company little credit, pointing out that it has sought to put in place data prioritisation, which would allow web companies to pay AT&T in order to get priority - i.e. quicker - access to their users.

"AT&T are lying when they say they support net neutrality, while actively opposing it," said Evan Greer, director of Fight for the Future, in an interview with tech news site Ars Technica.