European clubs have been given a final warning over financial fair play, as UEFA threatened to impose player bans and points deductions for the continent's worst offenders from the 2014-15 season.
Figures released by European football's governing body revealed that clubs lost more than 1.6billion euros (£1.33billion) in 2010 - a 36% increase and the worst statistics on record, with a survey of 665 clubs finding that 56% posted losses in the 2010 financial year, with 78 spending more than 100% of their income on wages.
UEFA general secretary Gianni Infantino revealed figures which show that only four of the top 30 leagues in Europe are breaking even, compared with 15 two years previously, and he told a briefing in Nyon: "This is the last wake-up call for everyone, this trend has to change very quickly to safeguard European football."
He added: "We must end this negative spiral and gamble for success. These losses cannot continue."
Under UEFA rules, clubs are allowed to make a maximum loss of 45million euros (£37.5million) over a two-year rolling period, followed by 30 million euros (£25million) for three years - moving ultimately towards breaking even.
But UEFA revealed that 13 clubs monitored in the 2010 financial year would have failed the break-even tests if the rules were applied now.
Warning that it would not put up with permanent losses, UEFA pointed out that 31 clubs, including four this season, have already been refused entry to its two main club competitions since financial licensing was introduced in 2004.
Lyon president Jean-Michel Aulas said there had to be a distinction between clubs spending "easy money, and money for investment".
He explained: "Tomorrow's model must be built on building stadiums and building youth academies - tangible assets that can benefit football in general."