More than one in five 14-year-olds had their English tests re-marked last summer - and 18,600 pupils were given a higher level as a result.

More than 600 secondary schools asked for 113,508 papers to be reconsidered through a group review, when an entire year’s papers are submitted, compared to 436 last year. A further 5,150 individual tests were reconsidered and 2,122 complaints about clerical errors.

There was also a huge rise in appeals by primary schools concerned that 11-year-olds were marked too harshly.

The Qualifications and Curriculum Authority is bringing in several changes this year to improve markers’ accuracy.

Both English tests were changed this year. The most controversial change, at key stage 3, was the introduction of a Shakespeare paper on which more than half the marks could be awarded without youngsters having to read or understand the Bard’s plays.

At primary level, more than 15,000 pupils had their English papers re-marked because heads did not agree with the result, an increase of more than 50 per cent on 2002.

The QCA agreed that 3,902 pupils deserved a higher level in English than they had previously been given. However, 209 were given lower marks.

A further 2,438 checks on clerical errors were made - an increase from 2,045 last year. At KS2, pupils could no longer choose which questions to answer but had to write a radio advert and a story based on four pictures showing a boy queueing outside a shop.

Jackie Bawden, head of assessment at the QCA, said: “We fully accept we gave markers a real challenge this year. There were major changes in 2003, particularly in the schemes for writing.”

Changes to be introduced this summer include an electronic check of whether the separate marks for each English paper at KS2 have been added together correctly and separate reading and writing markers for KS3 English.