The job was first advertised in October but the appointments committee readvertised it in November after failing to attract enough suitable candidates. The ESF has instead appointed the school's deputy principal Jane Foxcroft, who was one of the three short-listed candidates in the first round of interviews, as acting head.

Neal McGowan, principal of Larbert High School near Falkirk in Scotland, took part in interviews at the end of March, when the Association of Professional Teachers of ESF Schools voted to narrow its working practices over pay and benefits cuts of 9.2 per cent, and when parents reacted angrily to the announcement of fee rises.

But he told the South China Morning Post that he had made his decision for personal reasons.

'A large part of me wanted and I suppose still wants to take it,' Mr McGowan said.

'I did not want to say no. But there are professional commitments here that I have, things I have started and I really need to see through.' The ESF had given him extra time to consider, but it would have taken 'longer than it was able to wait' to settle affairs in Scotland.

He said he had been very impressed by West Island. 'The students are tremendous there and that was a big draw.'

Mr McGowan said the dispute between staff and management was 'not a factor' in his decision.

Julian Harniess, chairman of the APTESFS, dismissed Mr McGowan's excuse. 'That's ludicrous. Why didn't he think about that before he came over? It's absolute nonsense. He just didn't want it.

'We have said all along the ESF will find it difficult to get people. These are key positions, some of the most prestigious teaching jobs in the world.'

ESF chief executive Heather Du Quesnay said she was delighted Ms Foxcroft had agreed to head the school for the next year. 'She is a very experienced deputy principal who has been vital to the development of the school.'

Ms Foxcroft had not been offered the position initially as the foundation felt the school would benefit from someone from outside the system, with new ideas.

Ms Du Quesnay denied the two rejections reflected badly on the ESF.

'It does happen. It has happened in all the education systems where I have worked,' she said.

'Where we have been unlucky is that on two occasions we have identified a candidate and they have chosen not to take the post for personal reasons. I think that is a bit unusual, a bit of a coincidence.'

However, she pledged the ESF would review its recruitment process to make it more efficient.

The foundation has also needed to readvertise the post of principal of Clearwater Bay School after no appointment was made following a first round of interviews in March. Head of English at Sha Tin College and a leading English position at South Island School have also been readvertised.

Parent Guy Miller said: 'I am in recruitment. Can't they do it right? It's ridiculous they screwed up three times.

'It's bad for the image of the ESF. This is one of the best schools of its type in the world and they can't recruit someone properly.'

The foundation should have gained a commitment from the short-listed candidates before bringing them to Hong Kong that they would take the job if offered it.

But he was confident Ms Foxcroft would lead the school well: 'The staff they have got, including Ms Foxcroft, are very capable.'

Jacqueline Fok Hoi-lam, 17, a Year 12 member of a student panel that interviewed candidates, said pupils were 'all pretty disappointed' the school had been turned down again.

'This is one of the outstanding schools in Hong Kong and it deserves a good principal,' she said.