Government moves to crack down on poorly performing teachers to be unveiled today provoked a furious row with union leaders last night.

The Education Secretary Michael Gove wants to speed up dismissal procedures, allowing incompetent teachers to be dismissed within a term. At present, procedures can take up to a year to complete. He also wants annual checks on all teachers to ensure they are up to scratch and to lift any limit on the amount of time that can be spent on observing their lessons. At present, there is a "three-hour observation rule" limiting the amount of time a teacher can be observed in the classroom each year.

Christine Blower, general secretary of the National Union of Teachers, said the changes "will rightly be seen by teachers as an attack on their professionalism and will anger and depress them in equal measure". She added: "What the Government proposes is potentially a bully's charter... It is far better to improve teachers than to seek measures to sack them."