GREENPEACE has ended its 48 day occupation of Rockall after heralding as a "partial victory" the news that the Government will sign away rights to 60,000 square miles of the Atlantic Ocean around the granite out-crop.

Greenpeace's deputy executive director, Chris Rose, said: "Greenpeace wants nations squabbling over different territorial claims to agree that none of them will exploit the area for oil, in the same way countries have agreed non-development in the Antarctic.

"The world already has enough oil. If all existing reserves were burned we know it would lead to irreversible climate change, so why are we searching for more oil?

"The UK as a major industrialised nation needs to set an example for the world to follow. Robin Cook should now say clearly which areas of sea bed the UK will or will not develop for oil."

Fishermen are protesting over the Government's decision to sign away Britain's rights and members of the National Federation of Fishermen's Organisations have written to the agriculture minister, Jack Cunningham, over the move, which they claim could cost billions in oil, fishing and minerals rights.

The row centres on a Foreign Office decision, announced last Monday in a Commons written reply, to ratify the United Nations Convention on the Law of the Sea, an international treaty which prevents uninhabited rocks without an economy from being used as a basis for territorial claims.

Britain's most westerly claim will from next week be the islands of St Kilda, 100 miles off the Isle of Harris. Rockall remains part of the UK because it is within 200 miles of St Kilda.

Mr Rose said ratifying the convention may severely curb the UK's ambitions to industrialise the Atlantic.

"Twenty-two companies last week admitted that our proposed judicial review of licensing means they are no longer sure their licences are lawful and BP's Foinaven-ship, the supposed spearhead of the whole development, is still failing to produce any oil," he said. "It's time Tony Blair ... pulled the plug on this environmentally disastrous and out-of-date scheme."

But the problem for fishermen is that the ratification means Britain will immediately have to cede fishing and mining rights to an area that hinged on Rockall being the centre of the claim. Most of the sea aroumd the rock will be redefined as "international waters", open to negotiation between interested parties. The decision will also reduce European fishing rights to the North Atlantic.

Barry Deas, the chief executive of the National Federation of Fishermen's Organisations, which represents 2,000 vessels in English, Welsh and Northern Irish waters said yesterday his members were "totally sick of the way this whole thing has been handled".

It would have been better if the Foreign Office had consulted first before making the decision, he said, adding: "Essentially the Government has surrendered on British fishing jurisdiction . . . We've not even had a chart to see how it relates to the fishing grounds around Rockall. All we have had is bland assurances from MAFF that it will be all right ... We've written to Jack Cunningham asking why he has allowed this to go through without any consultation and await his answer with interest."

At the weekend, Bob Allan, the chief executive of the Scottish Fishermen's Federation, said: "The whole principle of giving up an area of that size is something we cannot support. It now means our boats will face international competition if they want to develop a fishery for unexploited deepwater species out there."

Legislation may be needed if British companies want to mine the deep sea bed under the terms of the Convention on the Law of the Sea.

Greenpeace is taking legal action against the Government for granting licences to companies in the area because it says mining will destroy rare cold-water coral reefs. Greenpeace claims the Government has broken European Union directives protecting species. The Foreign Office decision does not affect the High Court case because the mining is going on in British territorial waters.

But a Greenpeace oil campaign spokesman, Robbie Kelman, said the areas ceded to the UN should be declared a joint non-development area for fossil fuels, the chief cause of global warming. He said: "We welcome this. It gives the UK Government the opportunity to progress and tie in its environmental policy on protection of the world climate and its industry policy.

"At the moment these two policies are in stark contrast. One says we need to reduce our reliance on fossil fuels and the other is saying there should be ever more oil exploration. It is a completely contradictory policy for the Governnnent to follow."