The Conservatives' figures for scrapping tuition fees are being challenged.
Figures provided by the vice-chancellors' organisation, Universities UK, show funding gaps of hundreds of millions of pounds in the plans presented by the Conservatives.
While the Conservatives estimate that universities will lose a fees income of £700m a year - figures from vice-chancellors claim that the fees income has already reached £850m per year and could reach £1.5bn per year.
TUITION FEES TO BE SCRAPPED?
We cannot see how abolishing university fees leads to 'terrible cuts in student numbers' given that fees are themselves a barrier to university admissions
Damian Green, Conservative education spokesperson
At first sight, the Conservatives propose to deprive universities of a much-needed source of funding
Roderick Floud, Universities UK
The Conservatives have rejected claims that their plans could lead to large cuts in student numbers, saying they can fund the removal of student fees by abandoning plans to increase the number of university places and closing the Office for Fair Access.
And they say that this will balance the "foregone revenue" from tuition fees of £700m.
This £700m is taken from a figure given by the Education Secretary Charles Clarke, in a BBC News Online interactive forum.
Mr Clarke said that students currently paid £400m per year, which would rise when fees increased to £3,000 per year.
"Depending on what assumptions you make, that £400m might go up to £700m, £800m, £900m altogether - that would be the kind of order of it," said Mr Clarke.
But Universities UK says that the figure for £400m for this year - and the projected increase to £700m - only represents less than half of universities' income from student fees.
This is because only 40% of students pay full fees - and the £400m and £700m projections overlook the income received from the 60% of students who have all or some of the fees subsidised.
After means-testing, about 40% of students have all their fees paid for them and 20% have part of their fees paid - and universities say their budgets are based on this total income, not the smaller proportion in the Conservatives' estimates.
In terms of university revenue, if they were only to be compensated for the loss of £700m paid by students, this could leave them with a considerable shortfall.
For example, at present students pay £400m, but the university income from the student fees system is £850m. And they fear that scrapping the fees system would see this much larger figure disappearing from their budgets.
"At first sight, the Conservatives propose to deprive universities of a much-needed source of funding," says the president of Universities UK, Roderick Floud.
No 'terrible cuts'
The figure of £700m, which is for the money actually paid by students, rather than the much larger amount received by universities, is also queried.
The universities say that this is based on an assumption that relatively few institutions would apply the full tuition fee.
If most universities in England applied a full fee to most courses, Universities UK says the income from student fees would be more than £800m higher than the Conservatives' figures assume.
"Clearly we do not know how many universities will decide the proposed maximum £3,000 from 2006, but if most decide to charge the maximum for most of their courses, this could generate an additional £1.5bn for the sector," said Professor Floud.
But the Conservatives have issued a rebuttal of claims from the government that removing tuition fees would lead to cuts in student numbers.
"All that we would scrap is Labour's expansion and rigging of university admissions, which would provide us with the savings to scrap fees," said the Conservatives' education spokesperson, Damian Green.
"We cannot see how abolishing university fees leads to 'terrible cuts in student numbers' given that fees are themselves a barrier to university admissions," he said.