TUGS failed last night in a high tide attempt to save the crippled supertanker Sea Empress and, possibly, the lives of hundreds of thousands of sea birds.
Although the ship slowly see sawed from side to side as tugs tried to drag it to deeper water, it "appeared its central section was refusing to come clear of rocks just below the Pembrokeshire headland, St Anne's Head, near Milford Haven in Wales.
Tug boat crews' were called off shortly before 8.30 p.m. last night but three tugs were to remain near the vessel throughout the night.
A fresh attempt was planned around this morning's high tide at 5 a.m.
Salvage experts had brought nine tugs in hopes of pulling the giant vessel to a safer position to start off loading its remaining oil cargo. About 80,000 tonnes of North Sea oil remains aboard in damaged tanks the ship has already spilled more than 60,000 tonnes of oil into the sea, more than was lost in the Exxon Valdez disaster in Alaska in 1989.
A squadron of seven aircraft and counter pollution vessels brought from Liverpool worked until nightfall, attacking one slick eight miles long by one mile wide spreading from the tanker into the Bristol Channel.
With calmer seas after five days of storms, last night's operation took place at the highest tide in months and almost the last good chance for the international team of salvage operators to avoid a pollution disaster.
By 7 p.m. only half an hour before high water the giant vessel was swinging slowly through 45 degrees. The supertanker was lit by its own lighting system, with the navigation lights of the tugs adding to the illumination below the headland, showing patches of oil floating on the water.
Even if this morning's attempt to free the tanker succeeds, the effort has come too late to stop oil reaching the important island nature sanctuaries of Skomer and Skokholm, only a few miles from the tanker which is showing increasing signs of being in danger of breaking up.
The Sea Empress's cargo tanks suffered fresh damage when the vessel again broke free on Monday night.
Britain's shipping minister, Lord Goschen flew over the tanker yesterday to view the damage. He said "If Sea Empress remains in its current position, much longer there is a very high chance of her breaking up and all, the remaining cargo being lost."
At a crowded news conference in Milford Haven, he rejected angry allegations from environmentalists of oil industry complacency and a lack of specialist equipment available at the port to deal with the emergency more quickly.
"It has proved to be a most difficult and dangerous salvage operation. Weather conditions have been very adverse. People have been putting their lives at risk to make sure pollution is minimised," he said.
Large sea anchors were being taken last night to a position at the entrance of the estuary where the rescuers hoped to moor the Sea Empress.
Stephen Dennison, a leading salvage expert, said the plan was to deliberately sink the tanker on to the sea bed and then later bring in a smaller tanker to start receiving the cargo.
"Transferring the remaining oil could take one or two days," he said.
Ms Judith Phillips of Dyfed Wildlife Trust, which runs bird reserves on Skomer and Skokholm, said "Oil is now surrounding the islands it is just heartbreaking. If the pollution is allowed to build up it may take years for the islands to recover."
Among ships which inspected the South Pembrokeshire and the normally crystal clear waters around Skomer was the Earth Kind charity's Ocean Defender, a 200 tonne ex whaling ship.
Mr Robert Gross, one of the eight crew, said an oil tide mark could clearly be seen against Skomer's distinctive red rocks. Oiled guillemots and gulls were also visible.
"We sailed back to Milford Haven through part of the main oil slick. It was the most shocking and disgusting thing I have ever seen or smelt in my life," he said.