Headteachers are expecting “widespread problems” with the quality of marking of this year’s national curriculum tests, following the announcement last week that the release of results would be delayed this year.

Mick Brookes, general secretary of the National Association of Head Teachers, said he is expecting the number of appeals about Key Stage 2 and 3 marks to rise significantly this year, amid concerns that marking is being rushed to deal with a backlog of unmarked scripts.

He said he had already received a number of calls from heads who were worried about the accuracy of marking for key stage 2 tests for 11-year-olds.

“The row is only beginning,” he said. Mr Brookes is advising schools to issue returned test results as “provisional" - and to accompany these results with the teachers’ assessments of the levels achieved by pupils.

This was a reflection of the level of concern over disparities and mistakes in the marking of test papers taken by 11 and 14-year-olds, he said.

“We’re getting calls about the quality of marking. In one case there was no marking at all, the papers sent back to the school were completely blank," he said.

ETS Europe, which has this year taken over marking of the 9.5million national curriculum Key Stage 2 and 3 papers on a five-year contract worth £150 million, said last week that the results would be delayed due to administrative and technical problems.

Results for Key Stage 2 are now expected to be received by schools a week late on July 15, and for Key Stage 3 by the end of next week on July 18.

The National Assessment Agency, the government body responsible for the delivery of the tests, has given assurances that the marking will be as good as last year's.

But the unions say that ETS’s problems, coupled with reports from markers of serious problems with their training and the delivery of exam scripts, have shaken confidence in the entire system.

Martin Ward of the Association of School and College Leaders, also said that secondary school heads were also expecting marking of the Key stage 3 tests taken by 14-year-olds to be of a lower quality than last year.

“Because of the problems ETS has had this year, it would be surprising if there aren’t also problems with accuracy.

“The exam system is working absolutely to capacity and beyond,” he said.

He added that schools were concerned that they would not have enough time to launch appeals over grades.

Secondary schools are not expecting Key Stage 3 results until 18 July. Although the NAA has extended the deadline for appeals to 25 July, Mr Ward said this would not be long enough for schools breaking up for the summer holidays next week.

“If the head of English, Maths or Science goes on holiday on July 19, they will simply not have time to check the marked scripts by 25 July,” he said.

A spokesman for the NAA said that any school that had problems submitting appeals by 25 July could ask for an extension until 10 September.

The government has launched an inquiry, headed by Lord Sutherland of Houndwood, into the delays in publishing this year's test results.

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