Officials are wrestling with this problem in the review of placing requests ordered by the Education Minister last August, and further guidance is to be issued. But if eroding choice is ruled out the cost of cutting early years class sizes could soar to more than Pounds 12 million for additional teachers and Pounds 26 million for extra classrooms.
Parent choice could be left untouched, however, by the creation of composite classes spanning three years instead of two. This would restrict added teacher costs to Pounds 10 million and save on accommodation costs.
The Education Minister has committed himself in the past to flexibility in interpreting the Government's policy, so long as "the spirit of our commitment" is honoured. This could mean employing extra nursery nurses, classroom assistants or learning support staff in the early years.
But Ronnie Smith, general secretary of the Educational Institute of Scotland, made clear this week that simply improving general adult:child ratios would not be acceptable. Welcoming the Government's "important first step", Mr Smith said that class sizes now needed to be reviewed at all stages of education in the light of new courses, new ways of teaching and new technology.
Donald Gorrie, the Scottish Liberal Democrats' education spokesman, commented: "With ministers' commitment to sticking to Tory spending plans, parents can have no guarantee that this pay-out is not just a one-off."