A Scottish teaching union has come up with a radical solution to reduce staffing shortages: make teachers work longer.

An increase in weekly contracted hours from 35 to 37.5, if accompanied by a proportional pay rise of just over 7 per cent, could solve three crises at a stroke, believes Greg Dempster, general secretary of AHDS, which represents primary-school leaders.

He says that Scottish schools are suffering from: a lack of core teachers and supply staff; the knock-on impact on development time for school leaders; and “the fact that no one has had a decent pay rise for years”.

Writing on the AHDS Facebook page, he said: “It seems to me that there is a possibility of tackling all three of these issues in one go – with other benefits too.”

Teachers already tend to work “far longer than their contracted hours”, he said, but his idea is “unlikely to add quite as much to actual hours undertaken” and would boost salaries and pensions.

Teachers who cover non-class contact time – allowing other teachers to prepare lessons and pursue CPD – could be “displaced”, said Mr Dempster. But, he added, that would result in a boost for Scotland’s much-depleted pool of supply teachers, and free up such staff to apply for roles created in some local authorities by the government's Scottish Attainment Challenge scheme.

Mr Dempster conceded, however, that the idea would not be realised unless the Scottish government “give up their obsession with teacher numbers” – a reference to a national policy which reduces local authority funding where the total number of teachers has fallen.

But the EIS, Scotland’s largest teaching union, has reacted angrily and described the idea as “incredible”.

A spokesman said: "This is a deeply worrying proposal which would lead to many class teachers losing their jobs while those remaining in post would see their already excessive workloads soar even higher.”

He added: “This particularly divisive proposal puts the perceived interest of promoted staff alone above the well-being of class teachers and the protection of a quality learning environment for pupils.

"The only aspect of this that we can agree with is the fact that all teachers should be paid more – but never at the expense of their colleagues’ jobs or their own health and wellbeing.”