Teaching leaders have declared their opposition to government plans for a five-yearly check-up on their ability in the classroom.
Under the proposals announced by schools minister Ed Balls, those who fail to have their licence renewed will be banned from schools.
Around 10,000 members of the National Union of Teachers have signed postcards expressing their dismay at the plans.
The union's general secretary Christine Blower said the response demonstrated clearly how education workers feel about the policy.
She pointed to the fact teachers already undergo a number of accountability measures from teacher training through to performance management and Ofsted inspections.
Mr Balls said the licensing system would help to raise standards in the profession, putting it on a par with doctors and solicitors.
If the proposals are accepted the new system could be in place from September 2010.
Written by Alan Douglas