The scottish Government has shifted its position on class-size legislation and is actively considering the option of lowering the current P1 class-size maximum of 30.
The move has been prompted by the decisions of two councils - East Renfrewshire and East Dunbartonshire - to allow up to 30 children in their P1 classes.
The councils argue that the legal maximum class size is 30 under regulations issued in 1999, rather than 25 as set out in guidance issued by the previous Scottish Executive, and they cannot therefore resist parental placing requests, despite the Scottish Government's target to have no more than 18 pupils in P1-3.
Ministers have been under growing pressure to make their guidance on maximum class sizes legally binding, following successful challenges last year in both East and West Lothian by parents seeking places for their children which breached the 25-pupil class limit.
At that time, the Scottish Government said it had no plans to review its legislation governing class size maxima; this week, however, in an apparent U-turn, it said it was looking at the option.
A Scottish Government spokesman said: "We need to ensure that legislation enables local and national government to set class-size limits and supports the rights of parents to make placing requests, and are considering whether current legislation needs to be changed across the country. The previous administration did not legislate to reduce P1 classes to a maximum of 25."
Schools Minister Keith Brown said there were no plans to change the placing request legislation.
It is understood that, if ministers were to change the current limit on the size of P1 classes, they would not legislate to reduce the P1 class- size maximum to their target of 18; a more workable figure would be somewhere in the 20s.
But ministers accept that this would not close the loophole either and one aide commented: "You cannot legislate around every policy objective, and the whole tenor and tone of the concordat is to work in partnership with councils."
Many councils claim the Government's target of having no more than 18 pupils in P1-3 classes is unachievable in the short term. A spokesman for East Renfrewshire Council said it would either have to replace 15 of its 24 primary schools to create the additional classroom space, or have two teachers team-teaching in a classroom to meet the target.
John Stodter, general secretary of the Association of Directors of Education in Scotland, offered ministers a potential solution. Rather than opting for new legislation, he suggested, the Government could introduce a new regulation under one of the existing education acts, giving authorities the explicit right to set class sizes.