Support for the deal, which protected Scottish teachers’ 35-hour week and gave them guaranteed non-contact time, has been far from unanimous. One teacher in five voted against the agreement in a ballot in January, and at last month’s presidential elections in the Educational Institute of Scotland, candidate Myra Armstrong won 40 per cent on an anti-McCrone platform. The EIS represents 80 per cent of Scottish teachers.

MsArmstrong was at the National Union of Teachers’ annual conference last week to warn against succumbing to the lure of McCrone.

Opponents say the deal puts more power in the hands of school management, while the 23 per cent pay rise over two years does not go far enough to make up lost ground.

Only one delegate at England’s three main classroom unions’ annual conferences voted against a joint motion to take action in pursuit of a McCrone-style inquiry - that delegate was Scottish.

The agreement negotiated by employers, unions and the Scottish Assembly in January, following last year’s McCrone report, setsa maximum working week of 35 hours, with a maximum class-contact time of 22.5 hours and 20 minutes for marking and preparation for every hour spent teaching. Teachers must undergo an extra 35 hours’ professional development each year, on top of the standard five INSET days.

Campaigners say the 35-hour limit actually extends the Scottish working week and depends on the Government recruiting more teachers, while the extra professional development time is equivalent to an extra week’s work and puts a further burden on teachers.

Any extra time, after teaching and preparation, is to be agreed locally. Opponents say that local agreements led to the ever-increasing workload for teachers in the first place, and that McCrone puts even more power in the hands of heads who will be given their own place on the teachers’ side in negotiating bodies.

Principal teachers - senior staff - are to undergo a job re-evaluation exercise which opponents fear could lead to pay cuts as schools struggle to square the increase in the wages bill.

Union leaders unanimously supported the deal, which is being phased in over the next five years.

Lone vote against motion, 16