Boston — Massachusetts charter school supporters have filed a proposed ballot question for 2016 to expand the number of charter schools allowed by the state.

The proposal is reigniting a familiar debate pitting supporters of traditional public schools and backers of charters schools, which also are public schools but operate independently from local school districts.

About 80 charter schools currently operate in Massachusetts; proponents say the tens of thousands of children on waiting lists to get into the schools are proof that more are needed.

They say the proposal would allow the state Board of Elementary and Secondary Education to authorize up to 12 new charter schools or expansions of existing schools each year — giving preference to applications from the state's lowest performing school districts and districts with significant charter school waiting lists.

Supporters submitted the proposed language of the ballot question as the first step in the long journey to the November 2016 ballot. They also will have to collect tens of thousands of voter signatures. But their cause already enjoys strong support in the governor's office.

Charlie Baker has long been a vocal proponent of charter schools. He's also named charter school supporters to two prominent posts in his administration — James Peyser as his secretary of education and Paul Sagan as chairman of the 11-member Board of Elementary and Secondary Education.

"I'm encouraged by the fact that charter school supporters are putting a question on charter schools and expanding the cap — especially in underperforming school districts — on the ballot," Baker told reporters recently. "That's something that's important to me."

Baker said he's hoping to file similar legislation sometime in the fall.

Critics of charter schools — chief among them the state's largest teachers union — aren't abandoning their opposition.

Massachusetts Teachers Association President Barbara Madeloni said the ballot initiative would "effectively obliterate any meaningful caps on charter schools and undermine our public schools and our communities."

Madeloni said that while supporters of the question say it retains state caps on the number of charter schools, it actually creates a second pathway for opening new charters that bypasses those caps and removes any meaningful restrictions.

"If this passes, then over time public schools in any given district — currently governed democratically by a local school committee — could be wiped out and turned over to private charter school operators," Madeloni said.

In theory, she said, the proposal would allow the state to add new charter schools each year until no district public schools remain.

The majority of charter schools in Massachusetts are known as Commonwealth Charter schools, operated independently of local school districts and union contracts. The state also has a handful of Horace Mann Charter Schools that operate with approval of the local districts and their teachers' unions.

The Department of Elementary and Secondary Education announced recently it has received proposals from 10 groups seeking to open new charter schools and 19 proposals from existing charter schools hoping to expand their enrollment.