Tommy Doherty, president of the Association of Educational Advisers in Scotland (AEAS), said his members - now typically known as quality improvement officers - are still smarting at their treatment by the teacher and local authority negotiators.

The Scottish Negotiating Committee for Teachers, which is responsible for advisers’ pay and conditions, has failed to come up with a settlement for advisers, Mr Doherty says. He dismissed the committee as “no longer having any relevance for us”.

On the eve of the association’s annual conference in Dundee this weekend, Mr Doherty, an adviser in North Lanarkshire, commented: “Recruitment and retention problems are coming to a head and there is increasing demoralisation among staff.

“Advisers feel their chances of career progression are extremely limited and we fear the trend of advisers drifting back into schools will increase.

Those who have come into the advisory service have traditionally come from the ranks of senior staff in schools, but the salary advantages now enjoyed by teachers makes that completely untenable.”

Advisers’ salaries are tied to the size of their education authority, which produces a range from pound;31,545 for an assistant adviser in the smallest authority to pound;46,668 for a senior adviser in the largest.

This compares to a scale from pound;36,414 to pound;64,620 for deputes and headteachers in primary and secondary schools.

Warning signals about the future of the service have also come from a review of its role by the association’s sister organisation south of the border.

A report from the National Association of Educational Inspectors, Advisers and Consultants notes “the discernible drift” by advisers into management posts in schools. There is also direct recruitment of headteachers in second and third-tier positions in local authorities, which advisers might traditionally have hoped to occupy.

These pressures have come at a time when the role of advisers is more complex than ever, the report states. They are expected to be the shock troops for the improvement agenda, delivering “support and challenge” to schools. Yet inspection reports repeatedly highlight the problems of quality assurance in education authorities, including the lack of suitably qualified advisers to work with secondary schools.

The report calls on the Association of Directors of Education in Scotland to enter into discussions with AEAS to find a way out of the salary difficulties. It also suggests the two bodies draw up a “national competencies framework” to bring more consistency to the advisory service across Scotland.