The comments come after a new Evening Standard/TNS Omnibus national opinion poll shows nine in ten of all voters oppose higher student top-up fees.
NUS said the new figures confirmed that the future of student funding will be a key issue on the doorstep during the election campaign. Through the Vote for Students campaign, NUS is pushing candidates to pledge to vote against any increase in fees in the next parliament and to pressure the government to introduce a fairer alternative.
A separate Ipsos Mori/ Union of UEA Students poll of voters released today shows top-up fee architect and former Education Secretary Charles Clarke is vulnerable, as 84% of his constituents in his Norwich South constituency oppose an increase in student top-up fees beyond the current £3,225 cap.
NUS President Wes Streeting said: "It is clear that a hike in fees would be spectacularly unpopular with students and their families, but also with the public at large who can see themselves being priced out of education by greedy politicians and university vice chancellors.
"Universities have failed to explain how they are using the income they have received since fees trebled three years ago, let alone what they would do with even more money from students' pockets.
"Students and their families are simply not prepared to pay more for less. On polling day we will punish those candidates who fail to come clean on their position. Those candidates who want the support of students and their families must pledge to oppose a hike in fees or pay the price."