FLIGHTS CANCELLED

And hundreds of flights from Heathrow, Gatwick, Stansted, Manchester, Luton and Birmingham have been cancelled.

British Airways has cancelled all domestic flights to all domestic airports.

An internal BA memo obtained by Sky News advises pilots: "The safety of our customers, crew and aircraft is of paramount importance and will not be compromised."

Officials said more airports could close completely as the ash drifts over the UK.

Airports are urging travellers to contact their airlines to check whether their journeys are affected.

Latest travel information - read how each of the airports is affected here.

More than 150 flights have been cancelled at Heathrow and 138 at Gatwick, including the majority of easyJet and Monarch departures.

Eighty flights have been cancelled at Birmingham.

A spokesman from National Air Traffic Services (NATS) said: "The Volcanic Ash Advisory Centre has issued a forecast that the ash cloud from the volcanic eruption in Iceland will track over Europe tonight.

"NATS is working with Eurocontrol and our colleagues in Europe's other air navigation service providers to take the appropriate action to ensure safety in accordance with international aviation policy."

NATS has the authority to close airpsace around airports - which it has so far done in Scotland - and will consider other airports as the day goes on.

Manchester Airport said flights would be cancelled and delayed between 7am and 1pm.

Some easyJet flights due to depart from Stansted Airport have also been cancelled.

Sky's Enda Brady, reporting from Heathrow, said things were only expected to get worse throughout the day.

"I've been told that there won't be any good news coming out of the airport today."

Brady said that arrivals from the USA were particularly badly affected due to the flight path.

Liberal Democrat Shadow Chancellor Vince Cable cancelled campaign visits to Dunfermline and Edinburgh due to the Scottish airport closures.

Passengers told Sky about massive disruptions to their plans.

One said: "I'm due to get married in Essex tomorrow and my family were flying in from Belfast. That's not going to happen now."

Another said he had been sent home from Manchester airport and told to ring Monarch for more information but it was impossible to get through.

The volcanic eruption was the second in Iceland in less than a month.

The heat from it is so fierce it melted part of the Eyjafjallajokull glacier, sparking huge floods.

Weather experts also said the ash could take a number of days to disperse.

Dr Matthew Roberts, from the Iceland Meteorological Office, told Sky News he believed that there were unlikely to be any more explosions.

He said that the fine ash particles being blown across Europe should only "pose minimal health hazards" to people in the UK.

The volcanic ash jams machinery on planes and there have been many instances of damage to jet aircraft in the past.

After the Galunggung volcanic event in 1982, a British Airways Boeing 747 flew through an ash cloud that fouled all 4 engines, stopping them.

The plane descended from 36,000 feet (11,000m) to 12,000 feet (3,700m) before the crew could manage to restart the engines.

Sky weather presenter Lucy Verasamy said: "The ash cloud from Iceland represents a risk to aircraft since it can damage engines.

"But in this instance it won't affect the weather - although massive and prolonged eruptions can cause a cooling of the climate."

POLISH PRESIDENT IN PLANE CRASH

Polish President Lech Kaczynski and scores of other people were killed Saturday when the president's plane crashed on landing in the western Russian city of Smolensk, officials said. Skip related content
Related photos / videos Officials in Warsaw confirmed that President Kaczynski was aboard the plane Enlarge photo Officials in Warsaw confirmed that President Kaczynski was aboard the plane Enlarge photo VIDEO: Putin and Tusk remember Poland's Katyn massacre. Enlarge photo The Smolensk regional governor, Sergei Antufiev, said the plane clipped treetops as it approached to land at an airport outside Smolensk and crashed, breaking into several pieces.

Russian television broadcast live footage showing the plane's wreckage scattered in a forest with parts of it still on fire.

Russian news agencies reported there were at least 80 people aboard the plane -- some reports said there were as many as 132 people on board -- and Antufiev said no one had survived.

"It clipped the tops of the trees, crashed down and broke into pieces," the governor of the Smolensk region, Sergei Antufiev, told Russia-24 television news network by telephone from Smolensk.

"There were no survivors."

The television pictures showed the plane broken into many pieces, including engines and a huge chunk of the plane's vertical stabilizer caked in mud, strewn over a large area in forest that was blanketed with fog.

Firefighters were dousing water on portions of the plane that were still ablaze while groups of security personnel in camouflage uniforms and clusters of investigators in civilian clothes inspected the wreckage.

The Russian foreign ministry told Interfax news agency that the plane had crashed in heavy fog.

Officials in Warsaw confirmed that Kaczynski was aboard the plane that crashed and Russian television broadcast video shot earlier Saturday of the president and his wife boarding the plane in Warsaw.

Polish foreign ministry spokesman Piotr Pszkowski said that the army chief of staff and Deputy Foreign Minsiter Andrzej Kremer were also on board the plane.

Russian President Dmitry Medvedev immediately appointed Prime Minister Vladimir Putin as the head of a commission to investigate the crash and sent Russia's emergency situations minister, Sergei Shoigu, to the site.

The aircraft crashed a few hundred metres short of the runway at the Severny airport outside Smolensk, ITAR-TASS news agency reported, quoting rescuers at the site.

The flight data recorders of the plane had not yet been located but experts were on the scene and the search for them was under way, ITAR-TASS said.

Kaczynski, the identical twin brother of former prime minister Jaroslaw, was on his way to attend commemorative ceremonies at the forest of Katyn in western Russia where 22,000 Poles were killed by Soviet troops 70 years ago.

The crash of his plane occurred three days after Putin and his Polish counterpart, Donald Tusk, together attended a memorial for the victims of the massacre at Katyn.

The Putin-Tusk meeting there was seen as a huge symbolic advance in Russia's often thorny relations with Poland.