Schools in Crawley closed their doors to pupils this morning as part of a one-day teachers' strike over pay.

Seymour First and Middle schools on Seymour Road, Broadfield, turned away all their pupils, while six classes at St Margaret's First and Middle schools in Ifield and a further four classes at Langley Green Middle School were closed.

The strike also affected thousands of London schools as the two largest classroom unions staged the one-day stoppage as part of their campaign for a boost to London cost-of-living payments.

The action was by the National Union of Teachers (NUT) and the National Association of Schoolmasters-Union of Women Teachers (NASUWT).

Up to 5,000 primary and secondary schools in the capital could be prevented from opening according to the NASUWT.

Teachers in and around London get extra pay because of the added cost of living in the capital. Schools in Crawley fall into the outer fringe zone.

The NASUWT wants the inner and outer London allowances to rise from £3,105 and £2,043 respectively to £6,111 - the same as for Metropolitan Police.

The fringe allowance covering outlying boroughs inside the M25 should also be raised to more than £2,000 from £792, the union said.

The NUT wants the inner London payment to go up to £6,000, the outer allowance to £4,500 and the fringe to £2,500.

In March, a one-day strike over the same issue by the NUT alone forced the shutdown of hundreds of schools in inner and outer London but ministers were unmoved.

NUT general secretary Doug McAvoy said: "London schools are suffering a severe recruitment crisis.

"They can't hold on to their teachers either because they can't afford to live in the capital. They are either leaving the profession entirely or leaving to work in areas where it is less expensive."

Education Secretary Charles Clarke was unmoved.

He said: "A teacher in London starting in 1997 has had their pay increased by 50%. Striking is simply not the answer and serves only to damage pupils' education."