The report from Brussels says unless extreme spending cuts are made UK public debt will rise from 60 per cent of GDP this year to 160 per cent by 2020, 406 per cent by 2040 and 760 per cent by 2060.
The report, which is based on a “no policy change scenario” lists the British economy as high risk.
The Telegraph says the UK Government is challenging the figures.
It quotes a spokesman as saying: “This report has no basis in reality and calls into question the ability of the EC to carry out credible economic analysis. It takes no account of any member state’s plans to reduce its debts and only shows what would happen if no government took any action to reduce borrowing for 50 years.
“The UK Government set out a clear plan to halve the deficit over the next four years.”