Forecasters predict temperatures are due to plummet

Ewen McCallum, chief meteorologist at the Met Office, said the vulnerable and elderly would be particularly at risk as temperatures fall.

He said it was important to give an "amber alert" to government, fuel firms, business and the health sector.

But he added the aim was to ensure forward planning, not to scaremonger.

'Mortality rises'

Mr McCallum told BBC Radio 4 Today's programme: "We are working with the Department of Health and what we are finding is admissions to hospital increase dramatically and mortality actually goes up dramatically in cold weather."

We have had a pattern of very, very mild winters over the last few years so this will come as a shock Ewen McCallum Met Office

He added that the aim was for "forward planning" to "make sure that government departments and business utilities have got their act together".

The government has identified fuel poverty as a major cause of death among those who are unable or cannot afford to heat their homes properly.

Mr McCallum said the Met office prediction of a cold winter was 66% likely to be proved correct.

He said the calculations were based on the "North Atlantic oscillation" - a measure of sea temperatures which normally correlate with weather patterns.

Present readings suggest there will be much less westerly wind, which brings milder air from the Atlantic.

He said: "We have had a pattern of very, very mild winters over the last few years so this will come as a shock."