Noncitizen New Yorkers would be allowed to vote in municipal elections, under a bill to be introduced before the City Council that could by one estimate enfranchise 800,000 new voters.

Details of the legislation were sparse Friday, but a previous version would have permitted noncitizens to cast ballots in the race for mayor, public advocate, comptroller, City Council member and borough president. The new voters would be able to register in political parties. It covered green card and visa holders who have lived in New York for at least six months. Immigrants in the country illegally could not vote.

"I've been supportive of the legislation in the past, and obviously I know that it's being introduced, and continue to be supportive," said City Council Speaker Melissa Mark-Viverito, who controls the council's flow of legislation.

Mark-Viverito's spokesman, Eric Koch, said the earliest a bill could be introduced is after the new year.

The speaker had been a co-sponsor of the previous bill, which was introduced in 2010 but died in committee amid questions about its legality and opposition of the mayor at the time, Michael Bloomberg.

Allowing noncitizens to vote would represent a further lurch leftward that's shaken City Hall since Bill de Blasio became the first Democrat in 20 years to be elected mayor and Mark-Viverito, his close ally, became the council speaker.

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Since taking their posts in January, the council speaker and mayor have enacted policies long on the wish lists of liberal immigration backers.

In July, he signed a bill to provide municipal ID cards to city residents, regardless of immigration status, after Jan. 1. Sponsors say it will allow people to come out of the shadows.

And Friday, he signed bills to bar the city from tipping off the federal authorities to immigrants in the country illegally who are in city custody and subject to deportation proceedings, except in rare cases. The law is similar to policies enacted this year in Nassau and Suffolk counties. Another bill would boot federal immigration authorities from office space at Rikers Island, the city's jail complex.

De Blasio, who did not support the past version of the voting bill, remained lukewarm Friday on the idea.

"The legislation I've seen so far, I think, has a number of challenges and issues that have to be addressed, so I was not comfortable with the version of the legislation that I saw, but I'm certainly willing to continue the conversation."

During the first 150 years of American history, 40 states and federal territories had allowed noncitizens to vote in local, state and federal elections. But the laws became stricter amid anti-immigrant sentiment, according to Ron Hayduk, a Queens College professor of political science who wrote a book on the topic and is a supporter of noncitizen voting.

He said that noncitizens can vote in seven U.S. jurisdictions, including Chicago and six towns in Maryland.