DAVID Blunkett has been gearing up for the conference round with a visit this week to the brothers and sisters at the TUC. Over a rather good lunch, Mr Blunkett is thought to have raised the differences in perception between the Government and the teacher unions on the delicate topic of linking their pay to the progress made by the children in their care. The Secondary Heads Association and the National Association of Head Teachers are not members of the TUC, but heroically made a special trip to Brighton to join their colleagues.