Britain will be engulfed by a second Arctic freeze over the weekend, stoking fears that thousands of homes could be without heating and mountains of presents could go undelivered over the Christmas period.

Heavy snow storms will affect nearly every part of the UK at some point on Saturday and Sunday, with plummeting temperatures struggling to climb above freezing, forecasters said.

Rocketing oil prices and restricted deliveries have already left families without fuel and the Government has warned the situation could become "very serious" if the cold weather persists.

A backlog of about four million parcels could grow during the predicted cold snap, as private carriers struggle to overcome delays caused by the first spell of snow and ice.

The Met Office has issued heavy snow warnings for northern Scotland, Northern Ireland, Wales and south-west England. Widespread ice was also expected in most parts of the UK during the rush hour.

Aisling Creevey, a forecaster with Meteogroup, the Press Association's weather centre, said the weekend's weather looked bleak for almost every part of the UK, with some areas experiencing "significant" accumulations of snow.

"Pretty much everywhere in the UK will be affected by snow showers at some point this weekend and temperatures will really struggle to rise above freezing during the days," she said.

The second spell of bitterly cold weather will heap more misery on families in the run-up to Christmas with some homes having to wait for as long as four weeks for oil to be delivered.

In the last month alone oil prices have jumped from under 40p a litre to more than 70p in some cases, amid allegations oil companies are fixing their prices.

Christmas deliveries have been hit hard with a number of Internet retailers stopping deliveries in Scotland.

Industry insiders said it could be the first year in which depots and offices do not clear all their gifts.

Simon Veale, director of parcel and carrier management firm Global Freight Solutions, said dealing with the backlog was like "bailing water out of a sinking ship".

"There are likely to be more than four million new parcels in the system every day this week on top of several million more which still had to be cleared from the recent extreme weather. If there are additional falls of snow, as the weather forecasts are suggesting, the unhappy situation will be compounded further still."

The Royal Mail is planning to deliver 7,000 rounds on Sunday to around one million addresses and the Association of Train Operating Companies said it will run "ghost trains" to help keep routes open and have hundreds of ground staff on duty to try to keep key junctions and points clear of snow, as well as clearing and gritting platforms and station approaches to improve passenger safety