The Government's decision to allow academy schools to hire unqualified teachers has been condemned by a leading education expert who said the move was "regrettable".
The plan "flies in the face of evidence nationally and internationally", according to Professor Chris Husbands, director of the Institute of Education at the University of London.
It also contradict the Government's own White Paper, setting out its aims for England's schools system, which says that best education systems around the world train their teachers rigorously from the start, he added.
Ministers announced last week that in future, academies can hire staff who are experts in their field who have not taught in state schools before and do not have qualified teacher status (QTS).
They argued it would allow these schools to hire professionals who are experts in their field, such as scientists, engineers, musicians and linguists who may not have QTS. But the move was met with anger from teaching unions, who insisted that all children should be taught by qualified teachers.
In a blogpost, Prof Husbands cited the 2010 White Paper called The Importance of Teaching which says international evidence shows that "the most important factor in determining the effectiveness of a school system is the quality of its teachers".
"The best education systems draw their teachers from the most academically able, and select them carefully to ensure that they are taking only those people who combine the right personal and intellectual qualities. These systems train their teachers rigorously at the outset."
Prof Husbands concludes: "The decision to remove the requirement that those teaching in (publicly-funded) academy schools should have qualified teacher status flies in the face of evidence nationally and internationally."
A Department for Education spokesman said: "We expect the vast majority of teachers will continue to have QTS, and no existing teacher contract is affected.
"Independent schools and free schools can already hire brilliant people who have not got QTS, and we are extending this flexibility to all academies so more schools can hire great linguists, computer scientists, engineers and other specialists who have not worked in state schools before. This additional flexibility will help schools improve faster."