Results were due on July 8 and problems have led headteachers to call for the national curriculum tests for 14-year-olds in English, science and maths to be scrapped.

Four South Holland schools – Spalding Grammar, Gleed Boys', Spalding High and Thomas Cowley High – have returned English papers to American company Educational Testing Service, which has the contract to mark them.

Results for the 128 Gleed Boys' students are back in maths and English, but science ones are still awaited.

Headteacher Geoff Cowley said: "SATs should be abolished. They are a waste of time and get in the way."

At Donington, 135 students took SATs and headteacher Martyn Taylor also wants them scrapped.

He said: "The English papers were a complete mess. They are badly marked and incorrectly marked.

"Considering the amount of money that's been spent on these tests, it's absolutely appalling. Do employers take any notice of SATs results? No."

Spalding Grammar School headteacher Nigel Ryan said results for its 119 students have been received, but the English papers will be sent for re-marking.

He said: "We're very disappointed with the unreliability of the English marking."

Tim Clark, head of Spalding High School, where 150 students took SATs will also return English papers for re-marking because of inconsistencies.

He said: "Students' GCSE targets are based on their Key Stage Three SATs. These are also published and used by Ofsted. It's unfair for a school to be condemned if its results are bad when they are not consistent and secure."

Primary schools have also experienced delays with the marking of their SATs.