Willie Madisha of the South African Democratic Teachers' Union said all his demands were met during talks with the education minister, Sibusiso Bengu.

He expected the agreement to be finalised after consultation with the union's 170,000 members.

A BBC correspondent in Cape Town says education is an emotive issue in post-apartheid South Africa, and an extremely sensitive area which the African National Congress government has struggled to tackle.

Many text books are in poor condition

The ANC has had to reform a system which favoured white pupils above black students under the apartheid era. It is also having to address a situation in which too much money is being spent on teachers and not enough on educational materials.

The government strategy has been to embark on a rationalisation programme. Under it, thousands of teachers could lose their jobs - unions say the figure would be 50,000 - and class sizes will inevitably increase.

The South African Democratic Teachers' Union says this is unacceptable. It has challenged the government to make job cuts in the Education Department's bureaucracy instead.

The dispute is seen as part of a much wider struggle in South Africa. As the government attempts to increase the competitiveness of the economy, it is coming into direct confrontation with the public sector unions from which it draws so much support.

And if the government is seen to back down to the teachers, it could soon face industrial action from other powerful unions.