The OECD said the UK economy may need more stimulus and a further round of quantitative easing may be necessary.
The OECD said UK growth remained flat, and is only expected to "pick up momentum" towards the end of next year. The Paris-based economic think tank forecasts that the UK economy will grow just 0.9% this year, after shrinking 0.1% in 2012.
Angel Gurría, the OECD's secretary general, said a "particularly bright spot" in the UK was employment figures.
More top news
Researchers believe they have found the wreckage of British explorer James Cook's ship "Endeavour".
Four kittens have been rescued from a fire by emergency services in California, USA.
A mother died after trying to save her three-year-old son when he fell down a cliff during a family hike.