Pupils will be off until after the weekend

Ross High at Tranent is part of a wider �43m Public Private Partnership (PPP) refurbishment project.

Head teacher Helen Alexander said the environment was unacceptable for the 800 pupils and for staff.

East Lothian Council said the school would remain closed on Friday and that urgent steps were being taken.

A council spokesman added: "Ross High School will be closed to all pupils on Friday, 29 October due to problems with ongoing building work.

'Wise move'

"It is hoped that the school will reopen on Monday."

Dunbar Grammar was closed for one day earlier this week for similar reasons

David Eaglesham, the general secretary of the Scottish Secondary Teachers Association (SSTA), said he was aware of the problems in East Lothian.

Mr Eaglesham added that it was a wise move by the head teachers to pinpoint them and that there were difficulties throughout Scotland with PPP education projects.

The East Lothian PPP involves the council, a management consortium called Innovate, contractors Balfour Beatty and a firm which has secured the maintenance contract.

The project began in January 2003, but there were difficulties with the original contractors Ballast plc, who went into liquidation.