'ESF education has to be affordable,' she said, acknowledging that there were a significant number of parents who could not afford the higher fees set by comparable international schools. But there could be some narrowing of the gap with these schools.

Fee increases did not mean there was no need to cut staff costs, she said. It would be a dereliction of her responsibility if she did not put the ESF's finances in order, particularly with the uncertainties facing the future of the foundation's subvention.

'The first requirement is to plan against future contingencies. The possibility of the subvention being reduced is a real one,' she said. 'If we find the subvention is secure we would plough the savings into development, such as professional development and reducing class sizes.'

She defended the need to cut teachers' costs, which account for 69 per cent of the ESF's expenditure. 'We want to pay our teachers well. But there is a difference between paying well and being a good employer, and having a situation where salaries are out of control.'

Sarah Rigby, chairwoman of the Joint Council of Parent Teacher Associations, acknowledged that parents may have to 'share some of the pain' but said ESF education had to remain affordable.

Fees are now $47,300 a year for primary and $78,600 for secondary.

'A significant number of parents are pushed to the limit to meet the fees, and yet the ESF is the only place they can go for affordable education,' she said.

'Although fees have not risen for several years a lot of parents' ability to pay them has been eroded by decreases in their salaries.'