Heads' leaders this week blamed extra workload, lack of funding, and deputies' general reluctance to become heads as reasons for the shortfall. They queried the Government's plan to make the NPQH mandatory in four years' time, saying it would simply make a bad recruitment situation worse.
Only 4,150 potential heads - including 250 who took part in a trial programme - signed up in the qualification's first year, which started in September 1997, compared to a projection of 5,000 by the TTA.
And only 750 people registered to take the qualification this term.
The figures are bound to cast a shadow over the Government's plans to make the NPQH mandatory for all new heads by 2002.
David Hart, general secretary of the National Association of Head Teachers, said this week that there could be no question of making the qualification mandatory until more teachers were coming forward.
The problem lay not so much with the qualification itself - although it could be improved - as with under-funding, he said.
It did not provide opportunities for deputy heads to have time off during the working week. The disappointing take-up also showed that people did not want to take on headship.
John Dunford of the Secondary Heads Association said the workload of deputy heads in secondary schools was now so great they were reluctant to take on the extra involved in the NPQH.
"Word's got around on the grapevine that it's no pushover and that there's a lot of written work involved," he added. Making the qualification compulsory was "both unwise and unnecessary".
However, the TTA is playing down fears of a recruitment crisis. A spokesman said that initial interest in a new qualification was always likely to drop off once recruitment moved into "steady state".
The TTA has admitted that it is concerned about the relatively low numbers of primary teachers joining the course. There are currently 11 primary teachers to every eight from the secondary sector on the scheme.
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