One of the Liberal Democrats' most vocal opponents of tuition fees has indicated he may accept graduates paying more for degrees under a different system if equality goals such as social mobility are protected.
Sir Menzies Campbell, the former party leader, who had said he would vote against the government if a rise in fees was put to Parliament, told Times Higher Education that it was difficult to find anyone arguing for individuals to pay less in the present financial climate.
Speaking in the run-up to the Lib Dem conference in Liverpool starting on 18 September, he said that provided a new system of payment was progressive, and did away with the current regime of fees and loans, then it may gain his support, even if, unlike a graduate tax, payments were made direct to universities.
Almost all Lib Dem MPs signed a pledge to students before the election to oppose a rise in fees, which could be recommended next month by the independent review of student finance led by Lord Browne of Madingley, the former chief executive of BP.
Sir Menzies said Lib Dem MPs would need to see the detail of Lord Browne's proposals before deciding whether they could support higher contributions under a new system.
However, he said: "All of the discourse has been based on the predication that individuals will have to make a greater contribution. The question is how that can be achieved in a way least damaging to social mobility and opportunity."
A system of tuition fees and loans was wrong, he said, as it saddled individuals with a large debt from the moment they started their course.
But he added: "Do we hear anyone arguing that in the present financial crisis it should be possible to create a system that does not include a greater contribution?"
Sir Menzies' view may be seen as a softening of position by the coalition, which is keen to find a solution to student finance that Lib Dem MPs can support.
Another Lib Dem MP, David Ward, a member of the select committee overseeing government policy on universities, went even further, saying he had changed his view on the issue.
Mr Ward, a former principal lecturer at Leeds Metropolitan University, said: "My view has changed over the years ... because I saw the need for more money to go into higher education and, coupled with the financial crisis, I do start to think, is it wrong for those that benefit to pay more?"
The coalition's manoeuvring on tuition fees began in July when Vince Cable, the Lib Dem business secretary, suggested payments should be tied to earnings, widely interpreted as a bid for a graduate tax.
Since then the government, including David Willetts, the universities and science minister, has steered away from the idea of a "full-blown" tax but still insists it is interested in a system of graduate contributions linked to income and the institution attended.
Mr Willetts said in a speech to Universities UK last week that such contributions needed to be higher than at present to sustain investment in higher education, but later added that the government wanted the system to be progressive.
He also disclosed that a decision on student finance was likely before other reforms - raising the prospect of a parliamentary showdown on the issue before next summer.
Last week, it was reported that ministers had been considering two ideas: an "equity contract", where graduates promise to pay a share of their lifetime income to their alma mater; and a loan system that costs higher earners more.
The issue will be a hot topic at the Lib Dem conference, where a number of MPs have tabled an emergency motion to discuss student finance. One of them, the Lib Dem MP for Cambridge, Julian Huppert, said he would be suspicious of any system that simply removed reference to fees and debt.
"If it is the same as we have now and we just change the language then I am not interested," he said.
Meanwhile, Aaron Porter, the National Union of Students president, said Lib Dem MPs would still be betraying voters if they supported any system in which contributions were based on a fee set by a university, rather than future income.
"Behind all of the confusing language and hyperbole there's a simple choice - whether you base the overall amount of a student contribution on prices, fees and debt or whether you base it on benefit in future earnings," he said.