Labour, Conservatives and Liberal Democrats all promise a pupil premium
Labour's Ed Balls stoked up the political battle over school funding - putting forward his own version of "pupil premiums" for poorer pupils.
The Conservatives and Liberal Democrats already have similar plans to give schools extra cash for each poor pupil.
But Mr Balls says his scheme was more affordable than his opponents.
The Lib Dems say Labour's plans offer no extra funding for schools - and the Conservatives reject the accusation of funding gaps for their plans.
Mr Balls set out his funding plans for schools, spelling out how per pupil funding would be protected and providing details of cuts.
He also challenged the Conservatives to explain the funding for two of their flagship education policies - free schools and the pupil premium - accusing them of a "credibility gap".
Under government plans, funding for each school child would increase by 2.1% in 2011 to 2013, he said, which would have to be set against expected cost increases of 1.6%.
There would also be £300m cuts to non-school sectors of the education budget - including £100m for start-up costs for breakfast and after-school clubs, £45m from Becta the technology agency, £55m from teacher recruitment and almost £20m from the exam watchdogs and regulator, Ofqual and the QCDA.
A further £200m in savings had still to be found, said Mr Balls.
The Conservatives and Liberal Democrats have both set out plans for a pupil premium - making them a distinguishing feature that had separated them from Labour's school funding plans.
Under a pupil premium schools to receive extra funding for teaching children from disadvantaged backgrounds - this extra funding follows the pupils wherever they are taught.
Labour has now backed the principle - so that all three parties will be approaching the general election promising a pupil premium as a fairer funding system.
Under Labour's "local pupil premium" proposals, money already designated to support poorer children would be used. Mr Balls says that it means a more transparent allocation of this funding.
The level of support would be determined locally, he said, with different amounts expected for different areas.
"It's up to the local community to decide how support will be allocated," he said.
Mr Balls said that a national scheme might be more desirable but that it was not affordable, and he claimed that the Conservatives had not explained how they would find the extra funding for a national scheme.
The Conservatives have rejected this saying that Mr Balls is wrong to suggest that paying more to the poorest pupils will mean less for other pupils.
"The Conservatives have been absolutely clear that the pupil premium is extra funding for schools," said a spokesman.
"The funding will be found from outside the schools budget. Schools will not lose out because of it."
The Liberal Democrats' schools spokesman, David Laws, described Labour's adoption of the pupil premium as "a pretty desperate attempt from Ed Balls to re-package existing deprivation funding for schools".
"What is missing is any suggestion of additional money."
Head teachers body the Association of School and College Leaders warned of difficulties in introducing a pupil premium at a time of restricted spending.
"The introduction of a pupil premium will need to be carefully modelled and managed. The government has accepted that a rapid introduction could financially destabilise a number of schools.
"It is essential to get the basic funding entitlement level right for all pupils as a precursor to the introduction of a premium for deprivation," said the association's policy director, Malcolm Trobe.