They want assurances on how information about schools’ performance is going to be presented.

The move reflects continuing concern about the reliability of free meals as the sole index on which the targets are based.

Brian Wilson, the Education Minister, has tried to go out of his way to reassure schools and authorities that he recognises the limits of the methodology.

But he is caught between New Labour’s determination to publish as much as possible on school performance and pressure from teachers and directors to await a more robust index.

In a letter to her colleagues, Shelagh Rae, president of the Association of Directors of Education, confirmed its position that targets should not be sent to the Scottish Office until the Minister’s action group on standards takes a final decision on publication.

ADES is opposed to publishing information which will identify schools and their targets. Directors fear this will lead to the “naming and shaming” of schools along English lines.

The Minister’s action group is still wrestling with the same issue after a sub-committee charged with devising a solution failed to agree.

Elizabeth Maginnis, the education authorities’ spokesperson, and David Miller, chairman of the Scottish Qualifications Authority, pressed for authorities to publish data which would identify individual schools.

They argue that the details would appear in school handbooks anyway, which would allow the public and media to name schools in an uncontrolled fashion.

They were opposed by the other sub-committee members - John Travers, the North Ayrshire director, Ronnie Smith, general secretary of the Educational Institute of Scotland, and Joyce Ferguson, the head of Abercromby Primary in Tullibody.

ADES acknowledged that it would be up to each authority to reach its own decisions. Edinburgh has already decided to ignore the advice and submit the targets.