Sen. Jeff Flake (R-AZ). Reuters/Henry Romero Republicans in the U.S. Congress are moving to repeal regulations adopted by the Obama administration in October that would have subjected internet service providers to stricter scrutiny than websites to protect customers' private data.

Senator Jeff Flake of Arizona introduced a resolution on Tuesday backed by 34 other senators that aims to undo the regulations under the Congressional Review Act, a typically-seldom-used law that GOP members in Congress are more widely applying to repeal recently approved regulations from federal agencies.

The resolution broadly seeks to prevent similar rules from taking effect as well. Flake had previously announced his intention to reverse the rules in an op-ed earlier this month.

Representative Marsha Blackburn of Tennessee, who chairs a House panel on telecommunications, introduced a companion measure on Wednesday. Republicans control both chambers of Congress.

FCC chairman Ajit Pai. Getty/Chip Somodevilla Last week, the Federal Communications Commission temporarily blocked one part of the rules that'd require ISPs to broadly engage in "reasonable data security practices" in the event of a data breach, just a day before it was scheduled to go into effect.

The halting was seen as a victory for ISPs like AT&T, Comcast, and Verizon, some of whom are increasingly interested in boosting their own online advertising presence. Groups representing major ISPs had previously petitioned the FCC to scale back the enhanced regulations. Consumer advocates opposed the FCC move.

Now, the entire set of privacy rules is on the chopping block. The most famous portion the rules would force internet providers to obtain consumer consent before using precise geo-location, financial information, health information, children's information, and, most notably, web-browsing and app-usage history for advertising and internal marketing.

In other words: ISPs would need you to opt-in before they were allowed to sell such data, instead of allowing it by default and having you manually opt-out.

This portion of the rules was not scheduled to take effect until early December, however.

FCC chairman Ajit Pai, nominated by Republican President Donald Trump on Tuesday to serve a new five-year term, told a Senate panel on Wednesday that consumers would have privacy protections even without the Obama administration rules.

Rep. Marsha Blackburn (R-TN). AP The privacy rules were approved in a party-line vote as a sort of follow-up to the 2015 Open Internet Order, which famously classified the internet as a public utility. That set the current net-neutrality rules — which forbid ISPs from blocking, throttling, or prioritizing sites as they see fit — in place, but also left the FCC in charge of ISPs' privacy regulations.

Republican commissioners including Pai said at the time that the rules unfairly give websites like Facebook, Twitter, or Google the ability to harvest more data than service providers and dominate digital advertising.

Sites like those are currently regulated under slightly looser privacy guidelines set by the Federal Trade Commission. In particular, they are not required to get opt-in consent before using your web-browsing and app-usage histories for advertising purposes. This is part of why you may see targeted advertisements as you browse online.

Groups representing major internet companies have also requested a reversal of the privacy rules, though, largely because of the precedent they might set for future regulations that could affect their ad campaigns. They've also argued that presenting barriers to their advertising policies could make it more difficult to maintain certain free services.

Consumer advocacy groups have said that any discrepancy in privacy rules is warranted given that sites like Google and Facebook are largely free to use, that ISPs are uniquely able to see everything you do online (though this isn't entirely black-and-white with all companies), and that switching ISPs is more difficult than changing websites.

Pai and other GOP officials have said they want to create a privacy framework that allows ISPs to be regulated under FCC guidelines that are similar to those from the FTC.

"All actors in the online space should be subject to the same rules, enforced by the same agency," said Pai and acting FTC chairwoman Maureen Ohlhausen in a joint statement upon the FCC's data security stay last week. "Until that happens, however, we will work together on harmonizing the FCC’s privacy rules for broadband providers with the FTC’s standards for other companies in the digital economy."

Federal Communications Commission (FCC) hearing room is seen in Washington February 26, 2015. The FCC is expected Thursday to approve Chairman Tom Wheeler's proposed "net neutrality" rules, regulating broadband providers more heavily than in the past and restricting their power to control download speeds on the web. Reuters/Yuri Gripas

Blackburn, meanwhile, wants to return all privacy authority to the FTC. "The FCC’s decision last October to unilaterally swipe jurisdiction from the FTC by creating its own privacy rules for ISPs was troubling," she said in a statement on Wednesday. "The FTC has been our government’s sole online privacy regulator for over twenty years. A dual-regulatory approach will only serve to create confusion within the Internet eco-system and harm consumers."

The FTC's ability to enforce ISPs is currently in doubt, however, due to an appeals court decision last year that deemed AT&T exempt from FTC oversight because of its status as a "common carrier" — a designation that was set in place for all ISPs by the 2015 net-neutrality order. Pai and Republicans in Congress have strongly opposed applying that status to ISPs, and are widely expected to try rolling back the current net-neutrality rules in some form.

That said, even if the Obama-era net-neutrality order is reversed, some ISPs like Verizon and AT&T would retain their "common carrier" status because they offer telephone services. Further action would likely be needed to restore FTC authority.

Democrats in Congress have criticized the resolutions.

"Big broadband barons and their Republican allies want to turn the telecommunications marketplace into a Wild West where consumers are held captive with no defense against abusive invasions of their privacy by internet service providers," said Massachusetts senator Ed Markey in a statement on Tuesday.

The American Civil Liberties Union also criticized Flake's proposal.

"With this move, Congress is essentially allowing companies like Comcast, AT&T, and Verizon to sell consumers’ private information to the highest bidder," said ACLU general counsel Neema Singh Guliani.

Additional reporting by Reuters.