Mr Brown, a prominent Educational Institute of Scotland activist and North Lanarkshire primary teacher, told a council meeting in Edinburgh that standards would be undermined if assistants were involved in direct teaching. “I have known of no other Government initiative in the past decade that has caused more discussion in primary classes up and down the length of the country,” he said.

A “vigilant” GTC would have to fight to maintain the standards it was set up to preserve, although any injection of extra resources was welcome.

Compton MacLeod, a Paisley primary head, said some members were old enough to remember the uncertificated teacher, one of the reasons why the GTC was set up. “All of a sudden we have a new grade of teacher called an adult,” Mr MacLeod said.

On the days a classroom teacher was absent it would be useful to have an adult in the room but assistants would be involved in teaching writing and number work. “This is a most serious situation and already there are pilots going ahead,” he said.

Norma Watson, past EIS president and a member of a national working party on assistants, said Scottish Office advice was that they would not be teachers, nor would they replace teachers. “I am comfortable with that statement, ” she said.

Tony Finn, a Kirkcaldy secondary head and convener of the GTC’s education committee, said actual teaching processes had to be under the control of teachers but there was scope for additional help in the classroom, playground and dinner hall. Teachers could benefit from support for a whole range of non-teaching tasks.

Ken Macleod, former director of education in Dumfries and Galloway, said the council should accept the extra hands in schools “in good faith”. Teaching was badly served by the ratio of professionals to non-professionals.

The GTC has already told the Scottish Office that assistants should have no place in teaching reading or mathematics.