More than 5,000 untrained teachers allowed to work in academies and free schools under the Government's education reforms will be told they must gain a formal qualification or face the sack if Labour win the next General Election.
Shadow education secretary Stephen Twigg said it was "unacceptable" that a Government which claimed it wants to raise standards in the classroom lets teachers who lack the proper training work in state-funded schools.
Mr Twigg told The Observer: "It is shocking that this government is allowing unqualified teachers into the classroom.
"High-quality teaching is the most important factor in improving education. We need to drive up the quality of teaching, not undermine it".
He said that during the first two years of a Labour government, unqualified teachers would be given access to training. If they have still not qualified at the end of that period, they would no longer have a job.