BOSTON — Supporters and opponents of a ballot question aimed at expanding the number of charter schools in Massachusetts have pulled in nearly $19 million in contributions heading into the final two months before Election Day.

Charter school activists raised $12 million, according to reports filed late Friday with the state Office of Campaign and Political Finance. That’s nearly double the $6.8 million raised by opponents of the question, including teachers unions.

The measure would let Massachusetts add up to a dozen new or expanded charter schools each year outside of existing caps.

Donors to the pro-charter school campaign include two prominent billionaires — former New York City Mayor Michael Bloomberg who contributed $240,000 and Jim Walton of Arizona, the son of Walmart founder Sam Walton, who contributed more than $1.1 million.

Another $5.5 million came from the New York City-based Families For Excellent Schools Advocacy, Inc. The group was founded in 2011 and said its mission is to “ensure that every child attends an excellent school by building coalitions of families and their allies and running campaigns that change education policy.”

The three biggest donors to the group Save Our Public Schools, which opposes the ballot question, are teachers unions: the Massachusetts Teachers Association, which contributed nearly $4.2 million; the Boston- and Washington-based American Federation of Teachers, which contributed more than $700,000; and the Washington-based National Education Association, which contributed $1.9 million.

Opponents of the charter school question put out a statement saying “Massachusetts voters trust public school teachers, not out-of-state billionaires, to do what’s best for our students.”

Great Schools Massachusetts spokeswoman Eileen O’Connor said the pro-charter school group is “proud to have the support of parents and community members across the Commonwealth” while the opposition to the question is funded by “special interest groups.”

The charter school question is one of four on the ballot, including a question that would legalize the recreational use of marijuana in Massachusetts

Backers of the legalization question Massachusetts raised more than $2.7 million. The bulk of the money — about $2.2 million came from a single Washington-based political action committee — the New Approach PAC.

Supporters of the question describe the PAC as “a foundation of philanthropists dedicated to reforming marijuana laws for social justice reasons.”

Nick Bayer, campaign manager for the Safe and Healthy Massachusetts Campaign — which opposes the marijuana question and reported having raised $363,000 to fight the measure — said their contributions came from “a broad coalition of support from the Massachusetts health care, addiction, and business communities.”

Supporters of a question that would ban the sale of eggs and other food products that come from farms where animals are confined to overly restrictive cages reported having raised $1.6 million.

That included a $143,000 contribution from the Maryland-based Humane Society of the United States and $250,000 from Maximilian Stone, managing director of the New York-based investment and technology development firm DE Shaw & Co.

There were no filings for opponents of the question.

There were also no new filings for another question that will ask Massachusetts voters if the state should issue a second slots parlor license.

Election Day is Nov. 8.


Online: http://www.ocpf.us/Reports/BallotQuestionReports