All existing charter schools have applied to become state schools, Education Minister Chris Hipkins announced today.

Ten have applied to become designated character schools and two to become state integrated schools.

The Ministry of Education will consult on the applications and assess them before reporting back to Hipkins next month.

He said he expected to make decisions on their future by the end of July.

Hipkins has also reconvened an advisory group to monitor the schools' performance while they remain charter schools.

National's education spokeswoman, Nikki Kaye, said the Government's announcement on what was in effect the schools' only lifeline was ridiculous.

"This is a really ridiculous assertion from the minister that this is somehow a signal that they're all onboard with government policy."

Act leader David Seymour said the Government had "cut the legs out from under" the schools and taken away the flexibility that made them special.

"The state system is rubbish, that's why we've had so many students failing, that's why charter schools, with their additional flexibilities, were necessary. The state school system that imposes a one-size-fits-all model has not worked for all students," he said.

Hipkins introduced the Education Amendment Bill, spelling the end of charter schools, in February.

"The Government's strong view is that there is no place for them in the New Zealand education system," Hipkins said at the time.

A designated character school is part of the public education system, is funded like other state schools, and must adhere to the national curriculum.

Five charter schools scheduled to open this year will no longer do so.

The existing charter schools have a combined roll of about 1300 students.

Hipkins wanted existing charter schools to wind up before the end of their contracts by mutual agreement but if early termination was not agreed by both parties he reserved the right to issue a notice of "termination for convenience", by the middle of this month.

The final cost of removing the charter school model is unknown. Financial compensation for schools that have their contract terminated would likely cost up to $1 million in financial compensation to the schools, according to a Cabinet paper.

The schools were set up under National's agreement with the Act Party to cater for children who were struggling in the mainstream system.