English graduates are more in debt than their American, Canadian, Australian or New Zealand counterparts by the time they leave university, a report has found.
Those who graduated from English universities last year - under the £9,000 fees regime - owe an average of more than £44,000, data from the Sutton Trust shows.
American graduates owe between 29,000 US dollars (£20,500) - for students at public or private non-profit universities, and 32,600 US dollars (£29,000) - for those at private for-profit universities.
Called Degrees Of Debt, the report also highlights the growing complexity of arrangements in the UK nations, with different fee levels in Scotland for those from the rest of the UK.
The charity is now calling the Office for Budget Responsibility (OBR) to investigate the impact of the changes to grants and loans, to ensure value for money for students and taxpayers.
It is further recommending better co-ordination between higher education ministers from England, Scotland, Wales and Northern Ireland, and an annual assessment of the impact of tuition fees changes by the Business, Innovation and Skills (BIS) Select Committee in the House of Commons.
But the report notes that UK graduates benefit from an income contingent system. These are compounded by interest rates of up to 3% over inflation.
But some of their American counterparts face even higher interest rates, with loans that are not income contingent.
Australian and UK graduates are also able to take a "repayment holiday" when their income dips, with only 19% of US students receiving the most common federal loans enrolled on similar schemes.
The Sutton Trust is concerned that the abolition of maintenance grants this September will leave the poorest students with debts in excess of £50,000.
Sir Peter Lampl, chairman of the Sutton Trust and Education Endowment Foundation, said: "These debt levels are by far the highest in the English speaking world and are more than double average debt levels at universities in the United States, where students study for four year programmes, rather than three.
"They impact on the ability of graduates to go to graduate schools, to afford a mortgage, the timing of having children and other major life decisions.
"The cost of going to university has become so expensive that more young people should seriously consider higher level apprenticeships, preferably to degree level.
"By choosing this route they will earn while they learn, incur less debt, and develop skills which are greatly valued in the workplace.
"We need more good apprenticeships to offer genuine alternatives to university degrees."
Students who left Canadian universities last year were on average 28,500 Canadian dollars (£15,000) in debt, those leaving Australian institutions were 39,700 Australian dollars (£20,900) in debt, and graduates from New Zealand universities owed on average 50,000 NZ dollars (£23,300).