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.
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Aside from the heat, lightning storms may have kept you awake last night; the Met Office have warned more can be expected tonight.
The temperature is a little cooler, but it's still a very warm day