Concerns over English football's financial wellbeing are set to deepen further with the impending release of a report from Uefa which shows that Premier League clubs owe more money than all the other clubs in Europe's top divisions put together.

That finding is contained in Uefa's official report, The European Club Footballing Landscape, a copy of which has been seen by the Guardian, which analyses the 2007-08 annual accounts, the latest available, of all 732 clubs licensed by Uefa. It calculates the combined debts of just 18 Premier League clubs at just under €4bn (£3.5bn), around four times the figure for the next most indebted top division, Spain's La Liga.

Total Premier League debts were higher even than that – only 18 clubs are included in the report because two of the most indebted, troubled Portsmouth and West Ham, were not granted Uefa licences that year due to their financial difficulties.

The Premier League made much more money from television and other commercial income than its rivals, €122m on average at the 18 clubs; the next wealthiest was the German Bundesliga, whose clubs made an average €79m. Yet despite that commercial advantage, the 18 English clubs were hugely more reliant on borrowed money from banks and club owners than the 714 other clubs combined. "English clubs contain on their balance sheets an estimated 56% of Europe-wide commercial debt," the report says.

When it publishes the report in the coming weeks, Uefa will present it as authoritative evidence of the need for its Financial Fair Play rules, agreed in principle by the major clubs and leagues, which will require clubs to break even financially from 2012-13. In the foreword, Uefa's president, Michel Platini, says the figures demonstrate "increasingly clear warning signs" and argues Uefa's initiative is necessary "for the health of European club football".

Uefa's leadership makes a marked contrast with the silence at the Premier League and the Football Association over the debts at Manchester United and Liverpool, which now add up to more than £1bn collectively. Those huge debts were loaded on to the clubs by their North American owners' "leveraged" takeovers, yet despite the furore and mass supporter protests particularly over United's £716m debts, neither the Premier League nor FA have voiced any concern. Uefa, in its report, identifies United and Liverpool's debts as highly significant to the Premier League's overall indebtedness, and criticises the effect it has had on the clubs financially. "Just over half of [the Premier League's] commercial debt has been placed into the [relevant] clubs [or at a holding company level] recently as a result of leveraged buyouts," the report says, "so far acting principally as a burden rather than to support investment or spending".

The Premier League today defended the amount of debt carried by its clubs, arguing that as they make the most money of any in Europe, they can be expected to borrow more too. A spokesman pointed to the rules introduced by the league last summer, including a "going concern" test by which accountants will inspect clubs' books and financial projections, as evidence that the league is concerned about the issue. "The critical point is not the absolute size of any debt," he said, "but how sustainable it is."

However, the meltdown at Portsmouth, which followed the standard Premier League practice of borrowing from an owner and banks to pay high wages for otherwise unaffordable players, has seriously shaken the credibility of the English league's model.

Gianni Infantino, Uefa's general secretary, cited the report's finding that almost half of Europe's top clubs, 47%, made a loss in 2008 despite record revenues, together with the Portsmouth crisis and scale of Premier League debts, as evidence of the need for reform. "The Portsmouth example shows something must be done to help the clubs be more sustainable," he said. "The English Premier League clubs have higher revenues, but it is worrying to see such huge debt. If it is borrowed to fuel spending on players, the problem comes when you cannot borrow any more money and can no longer pay the debts."

The Premier League and FA have accepted Uefa's break-even rule, but continue to argue that owners, so called "benefactors", should be allowed to put money in to fuel spending on players. Infantino, however, was adamant that when the rule is implemented, clubs will be expected to run within their income, not have backers enabling them to overspend.