Test papers for 11-year-olds this year were littered with marking errors, a headteacher said yesterday.
They included some pupils being marked down for correctly spelling "distinctive". The teacher had written in the margin it should have been "destinctive".
In addition, some marks had been totted up wrongly.
"There are lots of errors," said Rachel Ross, headteacher of Woolton Hill junior School in Newbury - who is reviewing the marks awarded for her pupils' papers..
"We feel somebody has rushed with the marking and didn't apply the marking scheme as well as they could have done."
Her claims came as the Qualifications and Curriculum Authority, the national curriculum watchdog, revealed that this year's test results for 11-year-olds had been delivered on time - following last year's fiasco when thousand were delayed for months.
"The time constraints are putting these people under a lot of pressure and very tight timescales... It's very frustrating."
The QCA said 99.9 per cent of the tests were made available to schools yesterday - the deadline set for delivery. It had set itself a target of 99.7 per cent delivery.
Andrew Hall, of the QCA, said: "The successful delivery of over 1.7 million results in three subjects, all marked during a six-week window, has been the result of close team working and a commitment to ensuring accurate and timely information is available on each child's achievements at the end of their primary education."
However, Christine Blower, general secretary of the National Union of Teachers, cautioned: "Without prejudice to the work done by markers this year, historically one in five grades have been inaccurate.
"This is a further reason why we need to see an end to high stakes testing and league tables which distort the education our children receive.
"The government needs to accept that SATs (national curriculum tests for 11-year-olds0 should go, they are not an accurate assessment of children's educational achievements and cause unnecessary stress for parents, children and teachers."
Most secondary schools will retest pupils upon their arrival in September, John Dunford, general secretary of the Association of School and College Leaders, said yesterday.
Secondary heads believe the verbal reasoning and numeracy tests they use give a far more accurate picture of the potential of their pupils than the SATs.
Correlation between the two tests is "poor", Dr Dunford added. Last year thousands of national curriculum tests were delayed - prompting an inquiry into the system which led to the resignation of Ken Boston, then head of the QCA.
Schools Secretary Ed Balls abolished tests for 14-year-olds after last summer's fiasco but insisted those for 11-year-olds should stay.
This year schools have ten days in which to lodge an appeal against the marks awarded for the tests.
Michael Gove, the Conservatives' schools spokesman is considering abandoning the primary school SATs - and moving them to the beginning of secondary schooling in an attempt to get round the problem of teachers spending too much time teaching to the tests.Reuse content