Patrick wants more charter schools

The proposal, which requires legislative approval, would create an estimated 27,000 new charter school seats in about 30 districts across the state, from Boston to the Berkshires, according to a copy of draft legislation obtained by the Globe. Lawmakers were briefed on the plan yesterday.

Doubling the charter school seats in those districts is far more aggressive than the initial plan Patrick outlined in January, and represents a dramatic departure for a governor who had previously resisted calls to lift the state-imposed limit on new charters.

The governor’s push comes as President Obama is threatening to withhold millions in federal stimulus dollars from states that hinder charter school growth. The US secretary of education, Arne Duncan, will join the governor at a press conference today unveiling the legislation, which will be filed today.

The governor’s office declined to comment yesterday through a spokesman for the state’s secretary of education.

The legislation was immediately applauded by charter advocates, who trumpet the independent schools as laboratories of innovation that provide an alternative for disadvantaged children seeking refuge from failing schools.

“Charter schools have proven themselves to provide high-quality public education,’’ said Marc Kenen, executive director of the Massachusetts Charter Public School Association. “There are thousands of students in these districts that are stuck in low-performing schools.’’

But leaders of many of the state’s leading education groups said the proposal would be economically devastating for school districts. Students who leave a public school district to attend a charter school take with them a slice of state aid, generally $9,000 to $15,000 per student. The amount is based on a complex state formula that, among other things, attempts to establish how much it would have cost to educate the students in their home districts, but superintendents say the state calculation puts the number too high.

Education leaders said the scope of the proposed charter expansion is far more dramatic than the Patrick administration had discussed with them as recently as earlier this week.

“I’m surprised and disappointed,’’ said Thomas Scott, executive director of the Massachusetts Association of School Superintendents, contending that the state needs to overhaul charter school funding. “We are stripping the neediest districts of necessary resources.’’

The state’s 62 existing charter schools, authorized under the 1993 education reform act, generally operate independently of local school districts and are not unionized. That has earned them the ire of local education leaders, who lose money to the schools, but have no control over them, and of the teacher unions, who have been key allies for Patrick.

While many legislators see value in charter schools, some are reluctant to support expansion without changing the way charter schools are funded so it is less harmful to local districts, said Representative Martha Walz, cochairwoman of the Joint Committee on Education. She said the committee is researching methods used by other states to fund charter schools and is considering whether to require a change in the formula for funding schools before the limit on charter schools can be lifted.

“If too much money leaves the district for charter schools, students who remain in the district could be disadvantaged,’’ said Walz, who has not taken a position on the governor’s proposal.

The state places a limit on the number of charter schools statewide, as well as limits in individual districts. While about 60 more charter schools statewide can open under current law, many urban districts, such as Boston, are near the local cap, which limits each district’s spending on charter tuition to 9 percent of its annual net school spending. The governor’s proposal would increase that limit to 18 percent, 6 percentage points higher than he proposed in January.

In Boston, the increase would add more than 5,000 seats, enabling many of the city’s approximately 16 charter schools to expand and opening the door for many new charter schools.

Statewide, districts eligible for more charters, chosen because of low scores on state standardized tests, have capacity for another 10,000 charter school seats under current law. Patrick’s proposal would raise that to about 37,000 seats.

Last month, Mayor Thomas M. Menino, a longtime charter school critic, attempted to counter the possible change, advocating creation of a type of in-district charter school that could be controlled by cities and towns, instead of by the state. The Boston school district expects to see about $50 million in state aid diverted next year to charter schools, which will enroll more than 5,200 city children. The Legislature will hold a hearing on Menino’s bill next week.

Earlier this year in his state budget proposal, Patrick attempted to link raising the charter school cap to changes in the funding formula, such as creating a separate pool of state aid for charters. But charter school advocates objected, fearing it could put them at greater risk of state budget cuts, and the governor later abandoned the plan.

That was not the only concession Patrick made to charter advocates in the revised legislation, showing just how much he has warmed to charter advocates, a group that includes several prominent business and civic leaders.

Initially, Patrick had proposed quotas for certain groups of students, such as those who are in special education or are English language learners, but he is now settling for establishing guidelines. Charter advocates worried that quotas would compromise the fairness of its open lottery system for student admission; they still have some concerns about the guidelines.

Glenn Koocher, executive director of the Massachusetts Association of School Committees, said Patrick is conceding far too much to charter school supporters.

“What can it possibly be but another indication that the charter school lobby is dictating state policy?’’ Koocher said. “Districts will lose more money, and the charter schools will laugh all the way to the bank.’’