The 40 councils have formed the 'New Deal Fair Deal' campaign, calling for a nationally set minimum level of funding for all pupils and a funding floor below which no authority should fall.
Alan Charles, education chairman of Derbyshire, said: 'There is no adequate explanation as to why Hertfordshire receives£2,370 per primary school pupil and Derbyshire just£2,173.
'The situation for secondary schools is much the same, Derbyshire receiving£2,789 per pupil while Hertfordshire's figure is topped by an extra£234 per pupil - a difference of£200,000 for the average-size secondary school.
He added: 'It is time the government ironed out the inequalities in the current funding system. We cannot wait until the end of its grant system review in 2002. Our schools need the extra cash and they need it now.'
The 40 local authorities have invited 200 MPs to a special seminar next week to explain the agenda for a fairer deal.