Internet companies and public-interest groups plan a "day of action" Wednesday to bring attention and buzz to the proposed rollback of Obama-era "net neutrality" regulations that critics say could lead to blocked websites and deliberately slowed internet speeds.

High-traffic websites — among them Twitter and Amazon — are expected to feature banners, pop-ups, or other alerts on the issue, timed to coincide with the final days of the comment period for the proposed new rules at the Federal Communications Commission.

So far, more than five million comments have been submitted to the FCC's website over the new rules proposed by the new FCC chairman, Ajit Pai. The public-comment period ends Monday. The Republican-controlled FCC could vote on the new rules later this year.

The expected internet mass mobilization pits internet companies and users against telecom companies that provide internet services — a political battle that stretches back about a decade.

Comcast Corp., Verizon Communications Inc., and AT&T Inc. have lobbied for the rollback, saying the regulations are unnecessary and could stifle investment in the internet. They also fear that the government could use the Obama-era regulations, or Title II classification of the internet, to regulate consumer prices for broadband services, threatening future revenue sources.

"It's déjà vu all over again," said Tim Karr, senior director for strategy at Free Press Action Fund, a nonprofit advocacy group and one of the organizers of the protest.

Participants, in addition to Twitter and Amazon, are expected to include Netflix, Etsy, Vimeo,  and Reddit. Google and Facebook have recently said they plan to participate, as well, according to published reports. Organizers include advocacy groups Fight for the Future, Demand Progress, and Free Press — some of the same activists who organized online campaigns to push the Obama-era FCC toward stricter internet regulations, which the Tom Wheeler-led FCC passed in 2015.

Some companies have been late to rally around the day of action. At the same time, Washington insiders say they believe that the action could be overshadowed by the drama over the stalled health-care legislation and the investigation of Russian interference in the 2016 election.

Comcast had no comment Tuesday on the proposed day of action, but the Philadelphia company has said that it does not believe the Obama-era rules — which include partly regulating high-speed broadband service as if it were a monopoly phone service — are necessary and that it supports an open internet.

Comcast CEO Brian Roberts said in a blog post in late April: "We don't block, throttle, or discriminate against lawful content delivered over the internet, and we are committed to continuing to manage our business and network with the goal of providing the best possible consumer experience."

Comcast is the nation's largest residential internet provider, with more than 23 million broadband subscribers.