Wales' education minister has hit out at the findings of the Browne review into higher education in England.
Leighton Andrews said the proposals, which allow an unlimited rise in tuition fees, would destabilise higher education institutions in England.
They would also lead to reduced applications from low income families, he said.
Mr Andrews said the assembly government would digest the report over the next few weeks before responding in full.
Proposals made by the cross-party review led by Lord Browne allow for big rises in tuition fees in England's universities.
Other recommendations in the report include higher interest rates for the repayment of student loans.
The review was accepted by UK Business Secretary Vince Cable, who described them as "fair and affordable".
Mr Cable suggested that students might expect to pay fees of about £7,000 - more than double than at present - with the option of a higher level of fee.
Reacting to the report, Mr Andrews said that Lord Browne's review would shift the burden of paying for higher education from the state to the graduate.
This, he said, would result in a largely market-based system where institutions increasingly competed on cost not quality.
"We question the long-term sustainability of Lord Browne's approach in a world where higher education institutions in Europe are offering high-quality courses through the medium of English at low or no fees," he said.
"The Browne proposals, coupled with anticipated cuts in higher education expenditure, will mean a market in higher education that could destabilise significant numbers of HE institutions in England and lead to a reduction in applicants from lower income families."
Mr Andrews said that as around 16,000 Welsh undergraduates studied in England, the proposals would have a direct and immediate impact on Welsh budgets.
He said charging a £7,000 fee to Welsh students going to English universities could result in a cost to the Welsh Assembly Government of an additional £70m by 2015-2016.
Of this, £55m would effectively flow from the Welsh block into English universities, he said.
"We cannot afford to subsidise the higher education system in England," said the minister.
Mr Andrews added that it would be "premature" to issue a detailed response to the proposals immediately.
"We will digest the report and respond in due course, having also seen the final response from the UK government and the outcome of the Comprehensive Spending Review," he said.
Though devolution gives Welsh ministers the opportunity to diverge from English policy on universities, some educationalists fear the consequences of doing so in this case.
They have warned that an existing funding gap between English and Welsh universities could get even larger.
Andrew Parry from Glyndwr University in Wrexham told BBC Wales that a two-tier system where Welsh universities fell behind English ones was a distinct possibility.
National Union of Students Wales president Katie Dalton said: "The cap being raised is a disaster for Wales in that institutions in England will be able to charge more and Welsh institutions would be underfunded."
Amanda Wilkinson, director of Higher Education Wales said Wales could not become the "cheap and cheerful" end of higher education in the UK.
Ceredigion Liberal Democrat MP Mark Williams has said it would be "dishonest" if he voted with the coalition government to scrap the upper limit on university tuition fees in England.
Mr Williams said it was a "huge principle" and he would vote against it.