The company marking this year’s Sats has offered examiners a reward for getting through their allocation of scripts, amid continuing complaints of chaotic behind-the-scenes administration.

ETS Europe is offering a pound;100 bonus to markers who complete their standard allocation of papers by deadlines which are now three weeks away. Those who do not receive any scripts to mark are being promised pound;250 as compensation for the preparatory work they have already done.

But the pledges are doing little to placate angry examiners, some of whom gave up their half-term holiday last week to mark scripts that never arrived.

This follows markers’ unhappiness with the organisation of training events, computer software problems, and a helpline service described on The TES online staffroom as the “unhelpful line”.

One key stage 2 maths marker said he had had to cancel a planned holiday to Thailand after his scripts failed to arrive, denying him the chance to earn pound;900. He said: “I sat here all week waiting for these papers, and they never arrived. What has happened is almost laughable.”

David Gee, managing director of the National Assessment Agency, which is overseeing the marking, said last week only a minority of markers had had a bad experience.

However, an email sent last week by a senior marker supervising up to 100 marking colleagues and seen by The TES, suggests the problems are more widespread.

Addressed to “team leader” markers, it says: “I think it is fair to say that we have many frustrated markers; some being frustrated with the IT systems and others frustrated because they can’t start.

“We have a number of markers with no scripts and no immediate possibility of receiving any.”

The examiner said she had raised a string of problems with ETS and, to her “utter amazement”, had received an apology.

A National Assessment Agency spokesman added: “The external marking of the statutory tests is proceeding to schedule and schools will receive their scripts and mark schemes by the published deadlines. Approximately 10,000 markers required to mark the key stage tests have been employed.

“There has been no significant loss of markers this year.”