Student votes could have a major influence in deciding the outcome of the general elections according to the National Union of Students (NUS).
The NUS has warned that as much as 90 percent of voters oppose a rise in student top up fees.
So far 62 Scottish candidates have signed the ‘Vote for Students’ pledge, promising to vote against any increase in fees, including 39 Lib Dems, 18 Labour, three SNP, one SSP and one Green candidate.
Scotland has over half a million students, making up 15 percent of the voting age population, and 25 out of the 59 constituencies have more students than the constituency majority.
Liam Burns, president of NUS Scotland, told The Journal: "With increased fees we will see Scottish institutions struggle to keep up, and the potential for a brain drain from Scotland to the rest of the UK. Increased fee income is also likely to lead to cuts in public spending which can only have negative effects on the Scottish budget.
"In more than half of Scotland’s constituencies the student vote is large enough to completely change the outcome of the result. That's why we've been so successful at campaigning for MPs and candidates to sign up to protect Scottish students and vote against any increase in top-up fees, and will continue to do so right up until election night."
Edinburgh South is one of the closest marginal constituencies, where sitting MP Nigel Griffiths beat the Liberal Democrat candidate by 405 votes in the 2005 election.
Fred Mackintosh and Ian Murray, respectively the Lib Dem and Labour candidates in the constituency, have chosen to sign the pledge.
Another vulnerable seat is Charles Clarke's, former education secretary who brought in top-up fees. According to NUS, 84 percent of his Norwich South constituents are against top-up fees.
NUS UK President Wes Streeting said: "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."
Both Lord Mandelson and shadow universities secretary David Willetts have refused to discuss potential increases until the results of a funding review are known which will not be until after the election.
Meanwhile signed-up MPs claim that they are being bombarded with emails despite having signed the pledge. The website does not list the MPs and prospective parliamentary candidates who have backed it.