© The Sunday TimesIceland could be at the start of a surge in volcanic activity that may produce more eruptions
Parts of British airspace could be closed for up to three days from today because of volcanic ash from Iceland.

The ash could close some of the busiest airports in southeast England until Tuesday, the transport department warned yesterday.

At greatest risk today are Northern Ireland and Scotland, with more widespread airport closures possible on Monday.

Philip Hammond, the transport secretary, said the situation was "fluid", but that passenger safety was the government's top priority

Five-day ash prediction charts were made available on the Met office website for the first time yesterday. Previously forecasts were given only for the following 18 hours.

"We want airlines, other transport providers and the public to have the best possible information. However, the situation remains fluid and these forecasts are liable to change," said Hammond.

Passengers are advised to check with their airlines. Last week several airports in Europe were forced to close and flights were re-routed.

The prediction of closures from today until Tuesday is based on continuing volcanic activity in Iceland and prevailing weather.

The transport department said: "Within this timeframe, different parts of UK airspace - including airspace in the southeast - are likely to be closed at different times."

Ash from the Eyjafjallajokull volcano has led to the cancellations of thousands of flights across Europe and from north America, but recent changes in wind direction have meant that concentrations of ash over parts of northern Europe have risen above levels considered safe.

A spokesman for BAA, which operates Heathrow, Stansted and Southampton airports in the south of England and Glasgow, Edinburgh and Aberdeen in Scotland, last night welcomed the five-day forecasts.

However, he said that forecasts could change rapidly. "Over the next 24 hours we'll have a much clearer idea how it will affect southern England."

Dr Dougal Jerram, a volcanologist from Durham University, warned that the last big eruption of the Iceland volcano lasted for about two years in the early 1820s.