UK airspace could be closed again from tomorrow because of continuing volcanic activity in Iceland, the Government said today.

Disruption could last until Tuesday and could affect some of Britain's busiest airports in the South East, the Department for Transport warned.

Ministers agreed that, from today, five-day ash prediction charts should be made available on the Met Office website.

Previous forecasts were only given 18 hours ahead but the Government statement stressed that the new five-day charts will be based on assumptions about future volcanic activity and will remain tentative.

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

The Department of Transport said: ''Within this timeframe, different parts of UK airspace - including airspace in the South East - are likely to be closed at different times.''

Nats, the UK's Hampshire-based air traffic services provider, will announce any airspace restrictions if they become necessary and passengers are advised to check with their airlines before travelling to the airport.

Transport Secretary Philip Hammond said: ''The Government is carefully monitoring this situation and the safety of passengers will remain our paramount concern.

''We have taken the decision to publish five-day forecasts as we want airlines, other transport providers and the public to have the best possible information. However, the situation remains fluid and these forecasts are always liable to change.

''Nats - the UK's air traffic services provider - will advise of any airspace closures as and when they become necessary and I urge passengers to check with their airlines before taking any action.''

A spokesman for British Airways said meetings are being held with Swanwick-based Nats to work out the likely impact of the ash.

He said: ''There is a possibility of some disruption of airspace but we can't give any firm details yet.

''The public will understand if there are some disruptions. It is out of our hands.

''I don't want to jump to any conclusions - we don't know if it will even extend this far yet.''

BA is facing strike action in the coming days, potentially adding to travel disruption.