PRESSURE was mounting last night for an overhaul of national school tests after the resignation of a head teacher who doctored exam papers.

Stressed Helen Quick, 46, quit her job at Wyndham Primary School in Newcastle after confessing to education bosses she had altered answers in pupils' Standard Assessment Test (Sat) papers.

Union leaders said her desperate attempt came because she was under so much pressure to meet the Government's education standards and score well in their "dysfunctional" league tables.

It came as the exam board Qualification and Curriculum Authority admitted investigating around 100 similar alleged cases of misconduct last year and taking action in about 20 of them.

Earlier this month, The Northern Echo revealed thousands of Sat papers sent for remarking came back with higher grades.

Last night, Phil Willis, Liberal Democrat education spokesman and MP for Harrogate, led calls for the scrapping of national targets.

"What dominates schools is not the quality of education but the never ending levels of bureaucracy from the Government, reinforced by Ofsted and league tables and growing comparisons with neighbouring schools," he said.

"We need to scrap all the national targets. Key Stage 2 Sats (for 11-year-olds) have to be broadened to demonstrate added value."

National Association of Headteachers (Naht) regional officer, John Heslop said that head teachers were coming under increasing temptation to make "errors of judgement".

He said the Sat tests, which are not taken in Ireland or Scotland, needed to be abolished and league tables were "downright dysfunctional".

"In my opinion it is league tables which have led to the situation Helen Quick has found herself in," he said. "Her integrity before this incident was impeccable."

Mr Heslop said the marking errors revealed by The Northern Echo proved the "business of testing was an imprecise science".

Trevor Drury, head teacher of Hurworth Primary School, near Darlington, experienced the mis-marking at first hand when four resubmitted Sat papers came back with higher grades.

"All schools are under pressure to achieve the highest level of results," he said. "The assumption is that every year you will improve on the last one. They expect a steady curve but in the case of the vast majority of schools each year group is unique.

"We all want the best for our kids but we all want a fair system."

Miss Quick joined Wyndham in January 1994. The school was identified with "serious weaknesses" by Ofsted inspectors in 1998, who criticised its low standards.

But a re-inspection this year gave it a clean bill of health.

Union leaders said Miss Quick, of Gosforth, Newcastle, was concerned poor results could put it back in trouble. She changed wrong answers in the Sats for maths and science for her 11-year-olds, later confessing to her union.

Education chiefs said although the exam papers would now be annulled, youngsters at the school would not be affected.

Newcastle's director of education, Phil Turner, said: "While we very much regret this situation, it is important to stress that the children's education has not been affected in any way by this incident.

"Their education has always been of paramount importance to Miss Quick and she had an unblemished record until this incident."

Miss Quick is unlikely to be allowed to work as a head teacher again.

A spokesman for the Department of Skills and Education said the setting of ambitious national targets was "crucial" to promoting high standards and developing real improvements in schools.