Tony Blair's son Nicky is planning to join the National Union of Teachers in its first national strike for more than two decades. Nicky Blair, 21, is teaching at a comprehensive school in the West Midlands under the Teach First scheme, which aims to place talented graduates in inner-city schools.
A union source said that he would be joining the nationwide stoppage and may also attend a rally being staged in Birmingham to protest over teachers' pay.
His involvement emerges as Britain's biggest private teaching agency announced it would refuse to offer supply cover for striking teachers on Thursday.
The decision by Select Education, which supplies around 5,000 teachers to state schools every day, is bound to increase the number of schools likely to be forced to close for the day. Its stance is also likely to be followed by most other private teaching agencies.
John Donne, chief executive of Select Education, said: "We're aware of the sensitivities of the people that work in schools. What we don't want to do is to take sides in a situation like this and if we offered supply teachers to cover for those on strike it was felt that might be considered as taking sides. Of course, we rely on heads being honest as to why they want supply cover."
A survey of teachers carried out for the Times Educational Supplement revealed nearly half believed their school would be shut for the day. If that happens, more than 10,000 schools will close with about three million children being sent home. The NUT is striking over a 2.45 per cent pay award.