A former primary school head teacher has admitted forging tests - blaming the pressure of government league tables and money worries.

Alan Mercer, 46, who was the head teacher of South Borough Primary School in Maidstone, Kent, could face jail after pleading guilty to 14 forgery charges.

He told Maidstone Magistrates Court he had changed exam papers for national curriculum (SATs) tests and grammar school entry.

Toby Burrough, defending, said: "What he saw was pupils being compelled to sit exams when they hadn't finished the year's curriculum.

Frustration

"He was frustrated by the lack of progress being made. He essentially saw children who had a great deal of ability but weren't achieving that ability and weren't pushing themselves enough,"

Mercer was also facing "considerable" financial difficulties, with a great deal of pressure being placed on staff.

The court heard Mercer had changed numerous test papers taken by 11 year olds and had added answers on their behalf.

The results of Key Stage 2 tests were voided for all pupils at South Borough as soon as concerns were raised by the exams watchdog the Qualifications and Curriculum Authority.

Mercer, who was a teacher for 23 years, now had a career "in tatters", the court heard.

Mercer, who asked magistrates to take into account 140 other offences of forging exam papers, is to be sentenced at Maidstone Crown Court.

He was granted unconditional bail.

Doug McAvoy, the general secretary of the National Union of Teachers, said: "What this case does demonstrate is the huge pressure that targets and league tables place on teachers."

But, he added, this was "not an excuse for anybody behaving dishonourably and altering test papers".