The Parkhead club introduced the ban last year for 13-year-olds to reduce the wear and tear on young players and prevent them taking part in too many competitive games. This season the policy has been extended to 14-year-olds and will eventually apply up to the age of 16.

The Football League, however, proposes that a club “may permit” eligible players to turn out for their school - a move welcomed by the Scottish Schools Football Association. John Watson, the association’s president, said boys “should keep a foot in both camps” and warned against clubs cherry-picking from an elite pool of players.

Gary Mackay, manager of Airdrie, said there was “no question” of the First Division club’s youth players being banned from competing for their school. “Education is of the first importance and we want to encourage the camaraderie that is part of schools football. This system suits our development needs and we hope other clubs will follow our example.”

Tommy Docherty, a Glasgow teacher who last season coached his St Andrew’s Secondary under-13s to a league championship and the finals of the local cup, said the side played just 25 games in what was a busy season for a school team. “I see no reason why there couldn’t be a bit of come and go, allowing boys to turn out for both school and club.”

Eric Black, Celtic’s development manager, defended the “enormous benefits” brought about over the past 18 months. “We have also been encouraged by the positive support we have received from parents,” he said.