By Sean Coughlan
BBC News education correspondent
Students say the political parties are failing to connect with their concerns
Students say their campaign against higher tuition fees in England could decide the outcome of the election in dozens of university seats.
The National Union of Students says 1,000 candidates have signed its pledge against voting for higher fees if they are elected.
Students count for between 10% and 30% of voters in 45 seats, it says.
"Students look set to swing the election in a number of key seats," says NUS president Aaron Porter.
The NUS says that political parties are struggling to connect with the two million student voters - with almost no debate over tuition fees.
"It is still all to play for in this general election and all indications show that the student vote is still there to be won," says Mr Porter.
Students have accused political parties of hiding behind a review into university funding that will not report until after the election.
They were supported in this claim by the Institute for Fiscal Studies which published an analysis of manifesto promises for education.
"An issue as important as university funding should be part of the electoral debate, not kicked into the long grass," the report concluded.
The Labour manifesto promises extra places, but makes no commitment on how much students will have to pay - referring instead to the funding review.
The Conservatives also promise extra places and say that they will "consider carefully" the outcome of the funding review.
The Liberal Democrats are promising to phase out tuition fees over the next six years - at a cost rising to £1.8bn a year.
The NUS is mobilising the student vote to campaign against raising fees in England above the current level of £3,225 per year.
It has been pressing candidates to sign a pledge against raising the level of fees - and says that it has so far gained the support of 200 Labour, 13 Conservative, 400 Liberal Democrat, 200 Green and 200 UKIP candidates.
Among the prominent candidates signing the pledge are Phil Woolas, Tony McNulty, Nick Clegg and Vince Cable.
An earlier survey from Endsleigh insurance and the NUS suggests the student vote is waiting to be persuaded - with none of the parties so far having made much of an impression.
It claims that 75% of students intend to vote, but 81% "say they have never been contacted by any of the political parties".
According to this survey, two thirds of student voters could be swayed over the issue of tuition fees.
"As students prepare to vote in record numbers, the influence that we could have on this general election is unprecedented," said Mr Porter.
"With more than 45 vital constituencies around the country containing large student populations, the candidates who can effectively engage with this group are sure to reap the rewards on election day. No party can take the student vote for granted."