Two of English football's top-four clubs could be excluded from European competition in future as they fail Uefa rules that are about to be introduced.
The Financial Fair Play Regulations do not come into force until 1 June and will not really bite until 2013.
However, a study of recent accounts by BBC Sport shows Chelsea and Manchester City would fall well short of the rules if they were being applied today.
City were £110m in the red while Chelsea showed a deficit of over £50m.
Uefa's rules allow clubs to run up losses of £65m over the first five years.
Financial fair play has been introduced by European football's governing body Uefa to try and level the playing field between clubs funded by the super rich and those less fortunate.
In simple terms, teams cannot spend more than they generate from the football side of their business.
I don't think it will be difficult for the English clubs to comply because they are very well managed and very well aware of what is coming
Gianni Infantino Uefa general secretary
Uefa will have the power to ban any side that repeatedly flouts the rules from European competition.
The guidelines aim to measure a club's "pure" football business. Gate income, TV deals and sponsorship are all fine. Revenue from side businesses such as hotels and property would not be permitted.
Clubs can also offset their cost base by deducting from their overall football costs spending on infrastructure projects like stadium and training ground development and community investment.
Regular interest payments like the £45m a season paid by Manchester United are a genuine cost which would make it harder for them to break even. But one-off debt charges - like the ones United incurred in 2010 - would not be recognised by Uefa and that explains why, on the basis of the BBC's analysis, United would comfortably meet the criteria were they being applied today.
United made a pre-tax loss of £79m in 2010 but, by Uefa's measure, actually returned a positive break-even result of £42m.
Arsenal would also easily meet the guidelines, posting a surplus of £55m. With no single wealthy owner at the Emirates Stadium, they pride themselves on running a sustainable football business.
Football finance expert Andy Green, who writes the blog andersred, carried out the analysis of the clubs' accounts. He believes Chelsea and Manchester City in particular have a mountain to climb to meet the guidelines.
"For Chelsea, I think if they can get a bigger ground they can probably get there," he told BBC sports editor David Bond.
"For City, they've got a long way to go. They need to get into the Champions League, stay there year after year, probably put their ticket prices up and really turn around their commercial side - in fact they need to make it one of the best in the world - to even have a chance of meeting these rules."
Uefa general secretary Gianni Infantino said he was optimistic that English clubs would be able to comply with the rules though.
"I don't think it will be difficult for the English clubs to comply because they are very well managed and very well aware of what is coming," he told BBC Sport.
"There is sufficient time in order to implement the regulations. The English clubs are among those generating the highest revenues in Europe.
"The basic rule is the break-even rule that says you cannot spend more than you generate, so if you generate more than the others you have an advantage. So I am not worried at all about the English.
"I'm sure the managers of the English clubs are thinking about this, because they know the regulations are coming into force.
"They know what these rules mean and how we will implement them. I am sure that tomorrow they will put their finances in order so they are able to break even.
"Our president spoke to Manchester City's owners over a year ago when we started with this process and they were very happy with it."
Financial Fair Play rules good for English clubs - Uefa
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