Clubs such as Manchester United and Liverpool could be barred from future European competitions because of their heavy debt, a top Uefa official has warned Uefa general secretary David Taylor said clubs face the 'ultimate sanction' if they failed to deal with serious debts. 'There would be forms of communication, even warnings, even reprimands before one would ever get to a situation of exclusion but it's absolutely possible,' Taylor told the Leaders in Football Conference. Taylor expressed concern that clubs are putting their futures in jeopardy by exposing themselves to debt that would require a 'white knight' to bail them out. 'We are looking at strengthening the minimal financial criteria and other forms of self regulation that may impose greater standard on clubs that want to compete in European competitions and beyond that club football,' Taylor said. Although he did not mention specific clubs by name, Taylor's warning is sure to send a shudder through England's leading sides. According to Deloitte figures for 2006-07, all 20 Premier League clubs are in debt. But it's the likes of Manchester United and Liverpool who are most heavily burdened – and the global credit crunch will only increase the strain following their takeovers. United are estimated to be a staggering £764m in debt after Malcolm Glazer took over the club. Liverpool are around £350m in debt after Tom Hicks and George Gillet saddled the club with huge debt following their takeover. Plans for a new stadium have also stalled. Chelsea meanwhile are £736m in debt, although owner Roman Abramovich could wipe that out at any point. Arsenal's estimated debt of £318m is tied in with their new stadium and the Gunners have always been careful to reign in their spending and look after their finances. Yesterday, FA chairman Lord Triesman warned that clubs operating on enormous debt are at great risk, especially in this bleak financial climate.