Two more Wandsworth secondary schools have announced they are to become academies, despite opposition from teachers and unions.

Next month Balham's Chesnut Grove School and Tooting's Graveney School will gain academy status and will be funded and managed by the Department for Education rather than Wandsworth Council.

Academy schools have more autonomy and have flexibility over the curriculum with school governing body or trust having such powers as setting teachers' wages.

The council strongly supports the scheme, but the Wandsworth branch of the National Union of Teachers has spoken out against it and believes it will be detrimental to children's education.

A Wandsworth NUT statement said: "All the major unions representing classroom teachers and school support staff believe academy schools are detrimental to education and are extremely concerned that the spread of academy status to the point where local authorities are undermined will be problematic, not only for staff, but also for governors,parents and communities.

"In Wandsworth this process has already begun and the decision made by governors of Chestnut Grove and Graveney to transfer to academy status before the beginning of the next academic year despite opposition from staff, is disappointing.

"The notion of 'choice' for parents in education has always been a fallacy and is demonstrated by the fact that in Wandsworth few parents get allocated their first choice school. The reality is that academies will choose their students and more critically, their parents and this in turn will create an even more divisive education system."

There is currently only one academy in the borough, West Hill's Ashcroft Academy, but since the Academies Act 2010, the government has allowed and encouraged more state schools to become academies, as long as they meet certain criteria.

Chesnut Grove headteacher Magaret Peacock said of the school's decision: "Long term it gives governors more freedom but in the short term it gives us some additional funding.

"I do understand where they (NUT) are coming from. One of the freedoms the governors get is over staff pay and conditions - support staff and teachers.

"The teaching union in particular is worried the governors might worsen their terms and conditions.

"What my governors have said is they would genuinely need to be competitive. In order to be, they have got to offer good terms and conditions.

"I really don't think their worries are founded - they are comparing this academy to some of the older style ones. The older style were forced to become academies because they were failing."

A council spokesman said: "We support any moves and we think the headteachers and boards of schools have a duty to look into becoming an academy to see if there is any benefit to their pupils."

He also confirmed a number of other secondary schools in the borough had expressed interest in becoming an academy.