THE reliability of benchmark examinations was called into question today after it was revealed that papers from one school had to be re-graded.

Staff at St Augustine's RC High in Billington were so dissatisfied by the quality of external marking of this summer's Standard Attainment Tests (SATS) headteacher Anthony McNamara insisted on a re-mark.

And of 36 sample papers sent back to the national curriculum markers, every one was found to have been marked incorrectly, with 35 having to be moved up an entire grade level.

It is now feared the marking blunder could be "concealing a worrying picture" and spell yet another marking crisis to hit schools.

The National Union of Teachers, which is heading a campaign to boycott SATS tests at age 7, 11 and 14, said the news was "wholly damaging for schools".

The SATS exams, which cover English, maths and science, are used to gauge how pupils perform when they are all set the same questions and the grades are used to formulate league performance tables for schools.

But the latest exam scandal could force education leaders to reassess league tables if the basis for them is questionable.

Mr McNamara said today: "This shambles, whilst perhaps predictable, is completely unacceptable. Our fear is that the situation will worsen rather than improve.

"All these new tests require a massive army of markers and there are growing doubts about the competence of many of these particularly in the case of Key Stage 3 SATS."

Martin Fisher of the NUT said: "Quite apart from all the other concerns surrounding SATS tests, this questions reliability.

"Moreover league tables are damaging enough to schools. And if this means they could be based on unreliable information it makes them wholly damaging to schools in every way.

"We are aware of cases of remarking across the country and we will see an increase as teachers become increasingly suspicious and pressures grow.

"It is very worrying to think that practically every sample paper at this school was found to be wrong."

Dick Greenfield, national executive committee member for the NASUWT teaching union, said: "It could just be a one-off but there is every chance this is concealing a more worrying picture."

The majority of schools in Burnley today said they had not returned exam papers. But the head of Habergham High School, Stuart Smith, sent two papers back as a check.

"I find it very worrying that so many papers at one school could have been effected and it tempts you to send them back anyway," he said. "But our grades were completely in line with what we expected."

A Lancashire LEA spokesman said the decision by a headteacher to have papers remarked was "not unusual".