Dozens of schools will close when teachers stage their first national strike for 21 years on Thursday, it has been reported.

Ten schools in Hounslow will not open, and there will be restricted lessons in 10 others, according to The Guardian.

The newspaper polled local authorities on how many schools could be affected by the walkout over pay.

Twenty-five were able to give concrete figures and revealed 136 would close for the day.

The worst affected areas will be Suffolk and Cheshire with 28 closures each, the newspaper says.

Twelve will close in Cambridgeshire, 10 in Bedfordshire and nine in Brighton and Hove.

Two-thirds of schools have reopened for the summer term, leaving little time for headteachers to make contingency plans.

Schools minister Jim Knight said he was "disappointed" by the action, and that the Government had accepted independent recommendations for a three-year pay award with a 2.45 per cent rise in September, and 2.3 per cent in the two following years.

Mr Knight said: "We believe that all teachers should be teaching and talking - and not walking out."

The National Union of Teachers says three years of below-inflation pay increases would be "damaging" for the profession and make recruiting new teachers more difficult.

Christine Blower, acting general secretary of the NUT, said: "We would expect that in London very large numbers would close on the basis of the information we have. We don't expect any schools to be unaffected."