Teachers will today demand Birmingham's head of education abolishes plans to build seven city academies amid mounting criticism over the controversial drive.

Representatives from four teacher unions were due to meet Les Lawrence this morning for the first time since The Birmingham Post revealed the authority's proposals before Christmas.

City academies are Tony Blair's answer to failing schools and are backed by private sector sponsors who have a significant say over their management and curriculum.

Two of the unions present - the National Union of Teachers and the NASUWT - have already condemned the programme at their annual conferences.

Meanwhile, ex-Education Secretary and former Birmingham Labour MP Lady Estelle Morris also criticised private sector involvement in schools yesterday.

Her remarks came as think tank the New Philanthropy Capital warned potential academy sponsors the scheme was "high risk" and urged them to consider donating their money to other causes.

Birmingham maintains its proposals radically differ from the Government model - but the NUT claimed Birmingham's schools would effectively be "privatised".

Bill Anderson, deputy general secretary of the Birmingham NUT, said: "It will be privatised, it will be marketised. The best thing Birmingham could do is to hold back. That is what we will be saying to Les Lawrence."

The NASUWT, whose general secretary Chris Keates is married to Coun Lawrence, also expressed concern about private sector involvement in schools at their annual conference in Birmingham earlier this month.

David Ambler, Birmingham branch secretary of the Association of Teachers and Lecturers, added: "For teachers who may find themselves employed in academies it is the uncertainty we are concerned about."

Association of School and College Leaders' area convenor Mike Clarke said it would seek clarity from Coun Lawrence about the Birmingham academies.

Under the standard academy model, businesses, charities or wealthy individuals pay #2 million towards the #25 million rebuild of a failing school. A decision from the Department for Education and Skills is expected next month.