The California Senate today voted to approve the toughest state-level net neutrality bill in the US, one day after the California Assembly took the same action.

With both legislative houses having approved the bill, California Governor Jerry Brown has until September 30 to sign it into law.

The final vote was 27-12, with all 26 Democratic senators and Republican Senator Ling Ling Chang voting in favor. All 12 no votes came from Republican senators. In the Assembly yesterday, six Republicans joined 55 Democrats to pass the bill in a 61-18 vote.

"Today was a landmark in the fight to preserve a free and open Internet," Stanford law professor Barbara van Schewick wrote. "SB 822 brings back net neutrality to California and restores the important protections that the FCC voted to eliminate last December."

California's legislation "is the only state-level bill that truly restores all the 2015 net neutrality protections" and "sets the standard for other states to follow," van Schewick also wrote.

The bill was proposed by State Sen. Scott Wiener (D-San Francisco).

Advocacy group Fight for the Future called the Senate vote "a major victory for Internet activists who harnessed massive public outcry to pass the bill and a resounding defeat for big telecom companies like AT&T and Comcast, who lobbied fiercely against the bill and spent large sums on campaign contributions to California legislators."

Bans on blocking, throttling, and more

The bill would prohibit Internet service providers from blocking or throttling lawful traffic and from requiring fees from websites or online services to deliver or prioritize their traffic to consumers. The bill would also ban paid data cap exemptions (so-called "zero-rating"). It says that ISPs may not attempt to evade net neutrality protections by slowing down traffic at network interconnection points.

Broadband industry lobby group USTelecom urged Gov. Brown to veto the bill, saying net neutrality should not be enforced with a "state-by-state piecemeal approach." USTelecom CEO Jonathan Spalter claimed in his post-vote statement that "broadband providers strongly support net neutrality," but he didn't mention that USTelecom has consistently fought against both federal and state-level net neutrality rules. USTelecom has said it will sue states that enact their own net neutrality laws.