Nearly 400,000 graduates have not made repayments on their loans up to seven years after they graduated because they are not yet earning above the £15,000 threshold. It comes amid concerns that graduates now face the toughest time in a generation as firms cut down on recruitment in the credit crunch.

Stephen Williams, Liberal Democrat Shadow Innovation, Universities and Skills Secretary, said: “It is shocking that nearly a third of graduates are not yet earning enough to be repaying their students loans.

“Having forked out for at least three years to get a degree, many new graduates would be expecting to be in well-paid employment.

“Aside from their student loans, many of these young people will have also stacked up large amounts of commercial debt which they will be struggling to repay on their relatively low wages.

“As the financial crisis worsens the burden on new graduates is going to be even greater.”

The most recent wave of the Opinionpanel Student Voting Study shows student support for Labour has dropped dramatically.

By contrast, the Tory vote among students has been growing since David Cameron’s October 2005 speech to Conservative Party Conference.

Polls were based on the full time undergraduate student population, who represent around a million potential voters.

Students are an influential group, so shifts in their political allegiance are likely to impact on the views of both the next generation of voters and the future political scene. Today’s students are seen as tomorrow’s higher-earners and opinion leaders.

The most striking finding from these surveys is perhaps that the Liberal Democrats are much more popular among students than they are among voters in general.

The voting preferences of students over the last four years have been analysed by University of Essex professor Paul Whiteley.

Read his report