Schools were meant to transfer more than 20 routine tasks such as bulk photocopying to support staff by September 2003 at the latest, under the first phase of the workload deal between unions, the Government and employers.
But a National Association of Head Teachers survey of 1,567 schools conducted in May shows that, while 60 per cent had transferred the tasks, 5 per cent had not and 35 per cent were only making progress towards transfer.
Most of the schools responding, 1,381, were primaries. But the figures for secondary and middle schools were worse: only 47 and 54 per cent of respondents respectively had transferred the tasks. The special school figure was higher at 68 per cent.
The survey also revealed that many primary leaders spent between 60 and 120 hours a year covering for absent teachers. From next year the agreement is supposed to limit such cover to just 38 hours a year. The survey also found that 63 per cent of primary heads and 42 per cent of assistants and deputies lost leadership time because they were taking classes.
David Hart, the association's general secretary, said: "Everybody has assumed that the maximum 38 hours cover is only an issue for classroom teachers but it fundamentally affects many primary school leaders... This delivers the same message to government as our conference did, that we need clear and adequate funding if this agreement is to work."
The survey also found that 48 per cent of primary leaders said they did not have enough admin staff and 59 per cent did not have enough management time.
It follows a vote at NAHT's conference earlier this year to pull out of the agreement if the Government fails to come up with more money by the end of the year.
Meanwhile, the fall-out from the vote to pull out of the deal by the biggest support staff union, Unison, last week continues.
Its leaders have angrily condemned material sent by the anti-agreement National Union of Teachers suggesting an alliance between the two.
Christina McAnea, Unison head of education, said the NUT had spoken to her and had been arrogant in imagining it could speak for support staff. She said Unison would complain to the TUC and would not suspend its involvement in the deal before a meeting in September had examined progress made in renegotiating it.