Airport closures spread south and west as more air routes are suffocated by cloud

Britain is today bracing itself for what scientists warn could be weeks of disruption after experts predicted the volcanic dust cloud blanketing Europe will continue to cause chaos for the foreseeable future.

As first reports emerged of ash from the cloud landing in the south-east of England, meteorologists said volcanic activity in Mount Eyjafjallajokull, in Iceland, increased yesterday, forcing officials to extend flight restrictions yet again in an unprecedented air lockdown over much of the Continent.

With no sign of the eruption easing, volcanologists said ash, which is drifting in a cloud extending up from 8,000-30,000 feet and stretching across much of northern and central Europe, could disrupt flights for up to six months. Airlines cancelled thousands more flights this weekend, prolonging misery for millions of people.

Graeme Leith, who heads the Met Office's defence forecasting service, said: "This is Mother Nature. We're stuck in this phase until the volcano decides to sleep. Even if it cuts off today, which it shows no sign of doing, the ash would take another two to three days to fall out from the skies." Paul Knightley, of the forecaster Meteo Group, added that the UK could be in for "quite a prolonged spell" of problems.

"The activity has been quite vigorous overnight, causing the eruption column to grow," Icelandic geologist Magnus Tumi Gudmundsson said yesterday. "It's the magma mixing with the water that creates the explosivity. Unfortunately, there doesn't seem to be an end in sight."

Fallout from the vast ash plume stranded travellers as far away as Sydney. Delta Airways, Qantas, Virgin, British Airways and Cathy Pacific were among airlines to extend flight cancellations. At press time, Lufthansa grounded all flights worldwide until lunchtime today at the earliest.

World leaders are affected by the aviation lockdown: President Obama is expected to abort plans to attend today's state funeral of Poland's President Lech Kaczynski and his wife Maria in the Polish city of Krakow.

Consumers were warned that shops could start running low on supplies of fresh vegetables and fruit, and analysts said economic costs could spiral. Howard Archer, chief European economist at IHS Global Insight, said "the longer that the problem does persist, the more serious will be the economic repercussions". British and Irish scheduled airlines are losing up to £28m a day, with the total bill to European carriers hitting $200m, according to the International Air Transport Association.

One of the UK's biggest fresh fruit importers said business had ground to a halt. Anthony Pile, chairman of Blue Skies, said the company was losing £100,000 a day.

More than three-quarters of flights were lost yesterday across Europe, with barely 5,000 taking off or landing, the Eurocontrol air traffic agency said. This compares with 22,000 on a typical Saturday. Among the flights that did make it were three British Airways planes from New York, which scraped into Glasgow and Prestwick airports in Scotland.

Around Europe, 73 transatlantic flights landed yesterday morning, less than a third of the 300 that would normally arrive. The situation deteriorated from Friday, when 10,400 flights out made it out of the normal 28,000.

Met Office forecasters said it would take a prolonged change of wind direction for the situation to improve. "The UK and much of Europe is under the influence of high pressure, which means winds are relatively light and the dispersal of cloud is slow. We don't expect a great deal of change over the next few days," Mr Leith said.

Passengers anxious to get home are inundating the ferry companies. Most P&O crossings are booked up until Wednesday although the company is saving its remaining foot passenger services between Dover and Calais for anyone "desperate to get home", a spokesman said.

British Airways, which has cancelled all long-haul and short-haul flights into and out of the UK today, said it had no firm contingency plans on how to deal with the passenger backlog.

Hundreds of oil industry workers were left stranded offshore or waiting for flights onshore after all three North Sea helicopter operators were grounded in Aberdeen.

Despite reports of a sulphur-like smell and light coverings of ash on the ground in parts of Scotland, including Aberdeen, health officials continued to play down health risks.

Volcanic ash started falling out of a clear, bright sky in west London yesterday, with residents in Chiswick reporting dust on their cars. Scientists are now testing the deposits to ascertain if they pose any health risks. Initial tests from three samples of dust tested at Aberdeen, Lerwick and East Kilbride by the Scottish Environment Protection Agency suggested any risks were "minimal".

Mount Eyjafjallajokull began erupting last month, but it was only last Wednesday that its seismic activity became serious. Volcanologists are worried the eruptions could set off a sister volcano, Katla, which is much bigger. Because the volcano is situated below a glacial ice cap, the magma is being cooled quickly, causing plumes of grit that can be catastrophic to plane engines if prevailing winds are right, scientists said.

Sigrun Hreinsdotti, a geophysicist at the Faculty of Earth Science at the University of Iceland, warned: "Even if this stops right now we don't know if that's the end of the story. More magma pressure could build up and erupt elsewhere, possibly under Katla, which has a much bigger glacier so would be much more explosive."

Travellers' tales

Nina Biehal was unable to fly home from her holiday in southern France

"When we left Calais it was dark and bitterly cold and hundreds of people were queuing for ferries back."

Aoife Regan in London

"I should be in Dublin with the rest of my family for the christening of my twin nieces – it would have been the first time our family was together in two years, as my brother and his family are over from America."

Anthony Adeayo is trying to get home to Nigeria

"I have been staying in a hotel but have now checked out and do not know what I am going to do. I have limited financial resources here."

Kate Elliott's parents are stuck in Singapore

"I'm worried because my dad was in hospital before they went and he's had to go to a doctor there for more medication. They are so frustrated."

Professor John McCloskey was due to fly to Sumatra yesterday

"We're helping NGOs there to prepare for earthquakes. We've rescheduled for Wednesday, but having spoken to volcanologists I'm not confident that will happen."

Kelly Williams and Barry Stephens have been stranded at Gatwick since Friday and look set to miss their dream wedding in Antigua

"When they told me the plane had been cancelled I burst out crying. I've planned this for three years."

Sarah and Roger Priestly were due to fly back from Croatia to Dublin yesterday after a three-day break

"Ryanair has totally clammed up and won't tell us anything. So we have booked a ferry to Italy and plan to make our way towards Ireland by sea. We've decided to make an adventure out of it though. I've just been made redundant and Sarah works for the ambulance service and they have six personnel overseas."

Stephen Lewis at St Pancras

"I'm meant to be in Tenerife with my girlfriend. I get seven days' holiday a year, six now. My travel agency has been no help. I just want to get away somewhere."

Ryan Yoshinobu Barkataki in San Francisco

"I've got my final year hand-in for my post-graduate course on the 28th."