Willie Hart, the union's Glasgow secretary, said Holyrood teachers had threatened to boycott classes over fears about overcrowding and security. Last month a man masquerading as a pupil snatched a teacher's handbag. A knife was later found although it is not known whether it belonged to the intruder.
A spokesman for Glasgow's education department said that health and safety audits were being carried out by EIS representatives as part of a campaign throughout Scotland. Any specific recommendations would be taken on board. Checks on visitors were introduced 18 months ago and bids to install a new closed-circuit television entry system costing Pounds 36,000 are being considered.
Finbar Moynihan, the school's headteacher, said the city council had responded to problems he had brought to their attention.