Oil Slick Ireland
© Independent.ieThe huge oil slick on the Celtic Sea, less than 40 miles off the Kinsale coast. The giant Russian aircraft carrier The Admiral Kuznetsov, which is 300m long, can been seen to the top left of picture, giving an indication as to the immense scale of the spillage

A massive oil slick moving towards Ireland and the UK is more than three times larger than originally estimated.

The spill, about 50 miles south of Fastnet Rock, off the west Cork coast, was discovered near where a Russian warship was refueling in the Celtic Sea.

It is now believed to be 1,000 tonnes, revised upwards from 300 tonnes, and could reach Irish and Welsh shores in just over two weeks.

A Russian destroyer, a British destroyer, an Irish Naval vessel and a Russian aircraft carrier are all at the scene, along with an ocean-going tug and two refueling tankers.

The Irish government has asked the Russian embassy in Dublin to hand over samples of the oils carried onboard the Russian tankers and aircraft carrier.

While some of the slick - originally covering an area of around 2.8 miles by 3.1 miles - will break up or evaporate, the bulk of it is expected to remain on the surface, and is veering eastwards at around 12 miles a day.

A spokeswoman for Ireland's Department of Transport said: "The residual oil remaining is expected to develop into tar balls. Depending on weather conditions these may end up on the Irish south east coast in approximately 16 days time and also impact on the Welsh coastline.

"At this point it is too early to predict accurate volumes."

Both the Irish Coast Guard and the UK Coastguard are carrying out aerial surveillance flights, using special sonar equipment, over the area while a tug is being launched from Cork to carry out tests to see if the oil is recoverable at sea.

But authorities believe from past international experience that it is too difficult to contain and capture such a slick before it reaches shorelines.

Friends of the Earth, the environmental organisation, has described it as a "significant spill" bound to cause serious damage to marine life and has called for a full investigation.