London:
UK's airspace could be partially closed from Sunday until Tuesday due to a return of the Icelandic volcanic ash cloud and prevailing weather conditions which is likely to affect the country's main airports.
"Due to continuing volcanic activity in Iceland and prevailing weather conditions, there is - if the volcano continues to erupt at current levels - a risk of UK airspace closures early next week," the Department for Transport said in a statement.
"On current predictions, closures could begin as early as Sunday and are likely to last until Tuesday morning. The disruption could affect some of Britain's busiest airports in the South East, the Government said.
Within this timeframe, different parts of UK airspace - including airspace in the southeast - are likely to be closed at different times.
However, the predictions remain fluid and air passengers are advised to check with their airlines before taking any further action.
Europe's skies were shut for up to a week last month following the eruption of Iceland's Eyjafjallajokull volcano, in the biggest shutdown of the continent's airspace since World War II.
The volcanic ash, which can cause serious damage to jet engines, has continued to cause smaller disruptions in certain parts of Europe.
Meanwhile an expert warned that the last big eruption of the Eyjafjallajokull volcano went on for two years in the early 1820s.
"The volcano last went off with a big eruption in the 1820s, between 1821 and 1823 I think it lasted," said Dougal Jerram, a volcanologist from Durham University.
"Unfortunately the message is in that previous eruption, we know that the volcano can have a fairly protracted eruptive cycle. All we can do is look into past activity and from that we know the volcano can have eruptions that last a relatively long time.
"I think several months are certainly something that's quite likely in terms of its eruptive cycle. It's already been erupting for a month and it's not showing too many signs of calming down. I don't think it's going to stop soon."
The new Transport Secretary Philip Hammond said that passenger safety has to be the Government's top priority. Ministers have agreed that, from today, five-day ash prediction charts should be made available on the Met Office website.
Previous forecasts were only given for the following 18 hours 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.
British Airways is facing strike action in the coming days, potentially adding to travel disruption.
Today's warning of fresh problems came as it emerged Italy's civil aviation agency has fined Ryanair 2.5 million pounds for failing to help passengers stranded last month.