The Liberal Democrats reiterated their commitment to scrapping university tuition fees at their annual conference this week.
Sarah Teather, the party's Shadow Secretary of State for Innovation, Universities and Skills, accused the Government of conducting a "giant experiment" on students. "People are leaving university with mortgage-sized debt, and we have no idea of the implications for the individual or for the economy," she said.
The party's working group on higher and further education, headed by Stephen Williams, is consulting on a policy document that asks how students and the sector should be financed. Ms Teather insisted that the move was not an excuse to drop the party's commitment to opposing fees.
Former higher education spokesman David Rendel, who was at the forefront of the original campaign against tuition fees, said the party had been right to oppose fees in the past but had cited the wrong reasons.
"We said students would be richer if there were no tuition fees. We should have been saying that education is good for the whole of society - it is not just about money and jobs."
Ms Teather acknowledged that the party needed concrete proposals for funding the sector. "Long gone are the days where we can say, here is a wish list of 12 things we'd like to do," she said.
The working group will look at sources of cash, including contributions from business, hypothecated tax and alumni donations.
Bristol city councillor Neil Harrison, who works at the University of the West of England, cast doubt on alumni-giving for post-92 universities.
"Two thirds of my institution's graduates end up in the public sector - they will never be in a position to make massive donations for libraries," he said. "Maybe a percentage of donations to the Russell Group should be shared among the sector."