Hank Roberts (pictured), incoming president of the Association of Teachers and Lecturers (ATL), also said that government initiatives which are not properly trialled and evidence-based should be boycotted.
In his inaugural speech as president, he also called for the government to remove all asbestos from school buildings.
Mr Roberts, a geography teacher, said: “This September sees the opening of the first free school being run for profit as part of Michael Gove’s plans to privatise the whole of state education and open it all up for companies to make a profit from our schools. Allowing from October unqualified teachers to teach in academies as well as free schools is part of this plan.
“Many people realise that the government is privatising the NHS, but opposition to academies and free schools, while growing, is still not as universal as it should and must be.”
He also called for a strengthening of the auditing and oversight of finances in academy and free schools.
Mr Roberts has taught in Brent, London, for more than 30 years, first at Sladebrook High School as a geography teacher and then at Copland Community School, where he became head of geography. He will be leading a union which represents 160,000 teachers, headteachers, lecturers and support staff in maintained and independent schools and colleges.
Elsewhere, he said that too many new government initiatives are “not properly trialled or even trialled at all” before they are introduced.
He called upon the ATL to join with other unions and professional bodies to demand “proper scientific and reliable evidence before education initiatives are implemented”.
He added: “If the government fails to carry out proper research teachers should defend children’s education and their professionalism and boycott any spurious initiatives. We owe it to ourselves and our pupils. Education needs to be evidence-based in the same way as medicine is”.
On asbestos, Mr Roberts, who has spent many years campaigning on the issue, pointed to the example of Australia.
He explained: “Asbestos kills, some types more than others – but all kill. It should not still be in our classrooms.
“The Australian government has recently decided to remove asbestos from all its public buildings including schools and has set a deadline for this. I call upon the British government to do the same.”