Every child from a poor home would get a £2,500 boost to their education under the Liberal Democrats, party leader Nick Clegg pledged today.
The cash would be enough to bring the spending on their education up to the level of the average for children in independent schools.
The money is part of a £2.5 billion "pupil premium" scheme which would ensure all schools get a cash bonus for every child on free school meals they take on to their roll. The extra money is one of only two areas identified for a substantial injection of cash by the Liberal Democrats (the other is on green issues).
The pledge, made at a seminar hosted by the children's charity Barnardo's in London today, came as evidence emerged that poor children taught away from the inner cities did far less well in GCSE exams than those in urban areas where Labour had targeted most of its resources for fighting disadvantage.
"If you're poor and you don't live in the inner city, you have been forgotten by Labour," Mr Clegg said.
"This is the secret shame of a Labour party which promised that no-one would be left behind."
Figures show that youngsters on free school meals in urban areas - particularly inner London - have made substantial improvements in their GCSE results. Languishing at the bottom of the table for the performance on free school meal pupils are areas like Rutland.
In Kensington and Chelsea, 59 per cent of poor pupils get five A* to C grade passes including maths and English. In Rutland, it is 14 per cent. The gap is far wider than the gap in performance between rich and poor children.
Mr Clegg said the extra cash would allow the average primary school to reduce class sizes from 27 to 20 by giving them an extra £90,000 and the average secondary school would receive £400,000 extra to reduce class size, increase one-to-one tuition or out-of-hours catch-up classes for struggling pupils.
However, he stressed it would be left up to individual schools to decide how best to spend the money.
The extra cash would be found by making savings elsewhere in the education budget - such as scrapping education quangos, reducing spending on testing and the national curriculum - whose compulsory element would be reduced to a core curriculum in the basics. In addition, grant funding to the Academies Trust, which provides support for the Government's flagship new academies, would be slashed. Contact Point, a computerised scheme for sharing information on children - such as health or social care issues - would also go..
Mr Clegg defended his proposals, saying "education is everything" when it comes to reducing poverty.
The Liberal Democrats' proposal for a pupil premium has also been advocated by the Conservatives although so far they have not given precise details of how they would finance it.
However, in the event of a hung Parliament with the Liberal Democrats holding the balance of power, it looks like one idea on which progress could be made between the two parties.