FOUR more pupils gaining top GCSE grades could have saved Blackburn's Queen's Park Technology College, unions claimed today.

Officials said that if 19 pupils instead of 15 had picked up five A*-C grades this August, then the school's pass rate would have risen from 11 to 14 per cent -- above education bosses' threshold for action.

The pass rate made Queen's Park, already placed in special measures in February, one of the worst schools in the country and, along with falling numbers, prompted the decision to close.

Unions said indicators used by the authority to predict grades, show that around 20 per cent of the school's Year 11 pupils, some 22 out of 111 pupils, are expected to make the A*-C grades this summer -- taking the school above the government's minimum achievement threshold.

The school will shut in April and re-open a day later under a new name and identity with new staff - teachers have to re-apply for their old jobs. But the National Union of Teachers and the National Association of School Masters Union of Women Teachers are in 'utter disbelief' that the school's fate hung so delicately in the balance.

Union representatives are seeking to form a collective dispute with Blackburn with Darwen education authority which could lead to a judicial review. They have raised concerns over the April re-shuffle and want it delayed until September for the benefit of Year 11 pupils who they say will be disrupted before their exams.

Simon Jones, Blackburn secretary of the NUT, said: "Teachers are angry, stressed and emotional. We are very suspicious of how the consultation is being handled.

"If 20 per cent of pupils get the target passes then that matches the Department for Education and Skills floor target and would effectively take away any justification for this action.

"This puts in to perspective that the whole life of a school has been turned over because of marginal figures and we cannot accept it as a 'fait accomplis'."

Lesley Ham, secretary of the NASUWT, added: "The authority is simply making it up as they go along. There is utter disbelief what they are doing."

Chair of governors Peter Dawkins said: "Nobody is happy with this closure."

Nobody from Blackburn with Darwen Council was available to comment.