The UK's economy will slip back into recession in the coming months, the OECD predicted today.
A 'double-dip' recession will be accompanied by even higher unemployment figures, according to the think-tank, which said it should be tackled by yet more inflation-boosting quantitative easing.
The bleak forecast comes just a day ahead of George Osborne's Autumn Statement tomorrow, in which he is set to announce a series of measure to shore up the economy.
The OECD said the UK's GDP will shrink in the final quarter of 2011 and the first quarter of 2012 - the first time it has predicted a double-dip recession for the UK.
It believes the UK's faltering economy will grow by just 0.5 per cent in 2012, down from the previous estimate of 1.8 per cent, as it is hit by weak demand for exports, the Government's austerity measures and the squeeze in consumer spending.
The OECD also said unemployment, which currently stands at 8.3 per cent - its highest since 1996 - will rise to nine per cent in 2013 as jobs figures take a worse hit than in the recession following the banking crisis.
It said more quantitative easing - printing money - from the Bank of England would be 'warranted', adding that it expects the stock of asset purchases to rise to £400billion early next year from £275billion currently.
Mr Osborne is expected to announce a programme of 'credit easing' to help businesses when he addresses Parliament tomorrow.
The OECD said the slump will be modest compared with previous recessions and the economy is set to start recovering after two quarters of decline. It expects GDP growth of 1.8 per cent in 2013.
But it also warned that there are downside risks to its forecasts and the downturn could turn out to be deeper than projected, as the eurozone debt crisis has the potential to hit the banking sector and weaken confidence.
It warned that it may become necessary to pump more money into banks to help shore up the financial system. While it would be 'preferable' for banks to raise the money from private investors, it warned that the Government needs to be prepared to step in.
The Chancellor may also have to consider easing his programme of spending cuts but it warned that he will still have to increase austerity measures later on to ensure medium-term targets are met.
It suggested the Government could further increase the retirement age to improve long-term prospects.
And employment is likely to take a bigger hit this time around because businesses have less scope to reduce wages and adjust the amount of time employees' work.
The OECD called on the Government to pump more resources into employment training to help mitigate the impact of rising unemployment, particularly for young people who are already suffering a 20 per cent rate of joblessness.
With the eurozone already appearing to be in 'mild' recession, the OECD said the European debt crisis remains 'the key risk' to the world economy.
It added that urgent action was needed to stop the crisis from escalating, including a 'substantial' increase in the eurozone bailout fund.
The OECD also called for the European Central Bank to play a greater role in shoring up the finances of debt-ridden nations.
It said: 'If not addressed, recent contagion to countries thought to have relatively solid public finances could massively escalate economic disruption.'
Emerging nations are growing more slowly than previously and there is also a danger the U.S. could slip back into recession because of its austerity measures.
Asked about the OECD forecast, Chancellor George Osborne said: 'What is clear from the OECD is that these are very difficult times for many countries in the Western world. The OECD is predicting deep recessions in many European countries. That is a challenge for Britain.
'What we can do with our policies is take Britain safely through this storm. But we have got to lay the foundations for future economic success.'