Lawmakers in California's State Assembly have weakened a landmark bill aimed at implementing a local version of the Federal Communications Commission's now-defunct net neutrality rules, in a blow to Internet activists who had hoped for stronger measures.

Approved by the California Senate last month, the bill sought to impose strict regulations on how broadband providers, such as AT&T and Comcast, may handle Internet content. Key provisions not only banned ISPs from blocking or slowing down websites, but also prohibited the carriers from exempting specific apps and services from wireless data caps for an extra fee, a practice known as zero-rating.

The bill as initially proposed, SB 822, could have become the toughest such legislation in the country, with additional provisions that banned providers from charging websites extra fees to reach Internet users.

But in a vote Wednesday in a key State Assembly committee, lawmakers led by Chairman Miguel Santiago (D-Los Angeles) moved to strip the bill of some of its central components. The deleted provisions include the ban that prohibited ISPs from charging websites new fees to access customers, as well as the restrictions on zero-rating. Also deleted were a large section of definitions — without which California’s attorney general will have more difficulty prosecuting violations of the legislation, its supporters said.

The committee still sought to advance the bill, but the vote drew criticism from Internet activists who accused Santiago of being swayed by broadband industry lobbyists.

"The level of corruption we just witnessed literally makes me sick to my stomach,” said Evan Greer, a spokeswoman for Fight for the Future, an Internet advocacy group. "The actions of this committee today are an attack not just on net neutrality, but on our democracy.”

Campaign finance disclosures show that Santiago has received $22,600 in contributions from AT&T since 2014, and $4,500 from Comcast.

In spite of the changes weakening the bill, Santiago said Wednesday that he stands by the FCC’s 2015 net neutrality rules, and that the legislation as amended reflects the Obama-era regulations.

“Trump’s rollback of these regulations are a concern to me, as they should be to every American,” Santiago said in a statement. He also responded to his critics’ lobbying and campaign finance concerns as “irresponsible at best, and insulting beyond that.”

AT&T and Comcast didn’t immediately respond to a request for comment.

Internet providers have argued against tougher net neutrality rules on the grounds that the regulations could discourage investments in network upgrades and prevent ISPs from developing new business models. AT&T has previously urged Congress to write a national net neutrality law that would apply equally to broadband providers and Internet companies alike. Many of its representatives in Washington have called for something similar.

Sen. Scott Wiener (D), who introduced SB 822 in the California Senate earlier this year, said the amendments this week have effectively "eviscerated" his bill. Wiener downplayed the significance of the Internet providers' campaign contributions, saying the committee vote was the result of a simple disagreement among colleagues.

"We had a strenuous disagreement here, but to me, it’s not about campaign contributions," he said in an interview. "I will say, in general, AT&T and Comcast, they spent a lot of money in California targeting members with Twitter and Facebook ads, doing robo-calls to seniors telling them their bills are going to go up, that this bill is going to make your monthly payment go up. They flooded the capitol with lobbyists."

Despite the Assembly's changes to the bill, California could still wind up passing net neutrality legislation in some form in the coming months. The bill now heads to an Assembly committee dealing with privacy issues; further changes to the legislation could come at any point between now and the end of the legislative session in August.

Should a net neutrality bill be finalized, analysts say, it could invite a court challenge from Internet providers and possibly the FCC, whose current approach to net neutrality tries to ban states from circumventing its policies.

At that point, a lawsuit concerning the scope of the FCC's preemption powers would join the numerous other cases pending on net neutrality. More than 20 states have sued the FCC to overturn the agency's repeal of the national net neutrality rules. Meanwhile, opponents of the rules are waiting to hear whether the Supreme Court could take up a case challenging the regulations as they were approved in 2015.