The number of acting headships in Kent has grown from 23 in September 2003 to nearly 50 last month as the rate of retirements increases and schools find recruiting replacements increasingly difficult. The county council is now thinking of federating schools to cope with the problem.
David Hart, general secretary of the National Association of Head Teachers, said the Rewards and Incentives Group, made up of Government, employers and four teacher unions, had not addressed the problem in evidence on pay to the School Teachers' Review Body.
"It made it look as if teacher recruitment is buoyant but it did not mention the recruitment position for the leaders at all," he said.
This week the Secondary Heads Association submitted supplementary evidence, arguing that recruitment of school leaders remained difficult, and they should receive a higher increase than classroom teachers.
But John Dunford, SHA general secretary, said: "What is important is that we bring this issue to the attention of the STRB."