Striking teachers claimed schools have become “factories” churning out exam results and pupils with a limited education.

Unsustainable extended hours, pay freezes and restrictive syllabuses are hindering teachers' work, according to a group of union members working in Redbridge who spoke to the Guardian this morning.

But Michael Dance, teacher and NUT representative at Wanstead High School, said: “It is frightening the number of schools that are becoming factories without any thought for education.

“Teachers can no longer do what they want to do. I never thought I would see the day in schools when all kids had to do was pass an exam, leaving school without actually being educated.

“Conditions have worsened, we are working longer, we have had a three-year pay freeze and workloads are at an intolerable level.

“Michael Gove must start listening to teachers. We are here today to defend education and show that it is our children we care about.

“The strikes are often criticised heavily but all we are trying to do is send a message out to parents that we care. This is a positive strike, not a negative one."

Many experienced teachers are said to be fearful that reforms will mean more young people will be put off entering the profession.

Nigel May, a teacher in his 50s at Ilford County High, said: “I am not here for my own benefit. I have seen what privatisation has done to the rail network and other public services – imagine that happening to education.

“We are fighting for the future of British education and against the long term privatisation of schools.”

Kashif Mallick, secretary for Redbridge NUT, said: “It’s going to be a disaster. The shockwaves of privatisation would continue for several generations of children and teachers.

“The results are going to be seriously damaging.”

Education secretary Michael Gove, who is proposing to bring in performance-related pay and changes to pension schemes, accused teaching unions of being “idealistic”.

Gove said he believes the reform to teachers' pay would mean teacher and pupil performance would be better recognised and higher quality graduates would be attracted to the profession.

The government says it is aiming to improve the overall quality of teaching, allowing heads to get rid of under-performing teachers more easily and ensuring teachers take numeracy and literacy tests before training.