The Conservatives are still promising to scrap university tuition fees if they get into government, senior Tory Tim Yeo has insisted.
Tim Yeo is holding talks with university vice-chancellors
Mr Yeo appeared to hint on Monday that the policy could be ditched when he said he was "open minded".
But on Tuesday he told BBC News 24: "I am absolutely committed to ending the fees and particularly to opposing the government plan to impose top-up fees."
The shadow minister said he was talking to vice-chancellors about cash needs.
Duncan Smith's pledge
Currently, all students pay a flat annual fee of £1,125. Universities say this does not provide them with adequate funds.
Mr Yeo has held talks over recent weeks with the vice-chancellors of several leading institutions.
He said he wanted to be sure his party's policies met the "very real requirements" of the higher education sector.
The pledge to scrap tuition fees was a flagship policy of former Tory leader Iain Duncan Smith.
He had said he would do away with Labour's target of getting "up to 50%" of under-30s into higher education by 2010.
'Four square support'
Current leader Michael Howard's decision to retain the policy after he succeeded Mr Duncan Smith has been criticised by some within the party.
Former chairman Chris Patten denounced it as "tactically and strategically unwise".
Challenged several times during a radio interview on Monday, Mr Yeo declined to give a commitment that the policy would remain.
He said: "I am in discussions with the universities. I believe these are major national assets and they need to be cherished and developed and I am completely open-minded about how best that can be done."
But on Tuesday, he said he was "four square behind" the policy of "no fees, no small print", which is being touted round student campuses.
Mr Yeo said the party needed to look with an open mind at how much money universities needed, especially those trying to keep their world class status.
But top-up fees burdened students with too heavy debts, he added.
The National Union of Students estimates graduates will be left owing up to £30,000.
Some 159 Labour backbenchers have signed an early-day motion opposing top-up fees, raising the prospect that Tony Blair will be defeated in the Commons for the first time as Prime Minister.
The government is expected to publish the final legislation next week, with a Commons vote held later in the month.