Peter Peacock told the Headteachers' Association of Scotland (opposite page) that the Scottish Executive was "entirely on track" to deliver all the funding and all the teachers to meet its commitments to cut class sizes.
Both the Conservatives and the Scottish National Party have accused Mr Peacock of backtracking, breaking promises and hiding behind headteacher demands for flexibility as a means of wriggling out of the partnership agreement promise to cut all S1-S2 maths and English classes to a maximum of 20 pupils.
This week, Bill McGregor, HAS general secretary, expressed grave concerns about Mr Peacock's promises on staffing, warning that shortages of secondary teachers in some areas were "almost disastrous", leaving some schools unable to teach certain subjects.
"The minister really has to waken up to this. At the present moment in time there are dramatic shortages across the country in English, maths, modern languages and sciences and in some areas also in home economics and technical," Mr McGregor said.
Mr Peacock told the conference that by funding extra teacher training places at universities, the Executive had brought about 30 to 40 per cent increases in PGCE postgraduate course numbers this year, with more places being offered next year and in 2006.
And by concentrating these places in the subjects where they were most needed, PGCE places in maths had increased by almost 80 per cent and in English by more than 50 per cent.
Mr Peacock confirmed reports two weeks ago in The TES Scotland that he planned to offer secondary schools flexibility over class size upper limits in maths and English in S1 and S2.
He said that he would allow headteachers to vary the upper maximum of 20 pupils - to be brought in by 2007 under the partnership agreement - if "in the professional judgment of the headteacher and teachers, educational benefit would result".
"I have seen excellent practice in schools where flexibility in class sizes is making a real difference for pupils. Part of my theme has been to give more trust and discretion to headteachers and teachers and it seems to me there is in principle a strong case for what you have been asking."
Mr Peacock said he would be discussing the detail of how this might be achieved with various groups - headteachers, the teaching unions and local authorities.
Triple test for bigger classes
Three conditions would have to be fulfilled before the class size limit could be varied, Peter Peacock told heads.
* Every child in the target groups benefited from smaller class sizes.
* The proposal linked to the schools strategy being followed by the education authority.
* There was support from the parent body.