Its stance is likely to re-ignite the protests and provide Labour with one of its thorniest public-relations problems since taking office, especially as Michael Meacher, the environment minister, promised the Labour party conference last October: "There will be no more Brent Spars under Labour."
Greenpeace, which forced Shell, Brent Spar's operators, into a dramatic U-turn in 1995 with its campaign of occupying the installation and organising Europe-wide petrol boycotts, said yesterday the Government's move was "totally unacceptable."
Simon Reddy, the group's decommisioning campaigner, said : " This policy means there will be over 60 potential Brent Spars under Labour. So much for their promises. This is folly, and if the Government does this it will be dramatically at odds with international public opinion."
The vast majority of European countries want a permanent ban on dumping any disused oil installations in the sea.
However, in compliance with the wishes of the British oil industry, the Government is striving to keep a major loophole in the treaty to be signed in July which will prohibit dumping and insist that platforms be dismantled and brought ashore.
It wants a get-out clause for the biggest steel platforms, those in more than 75 metres of water and weighing more than 4,000 tonnes. The oil industry argues that dismantling some of these giant installations may be too technologically difficult, too dangerous, and - not least - too expensive, and, in some cases, a better option would be to topple them over where they stand, on to the sea bed.
"We need to look at large deep-water installations on a case-by-case basis, so that the solution takes account of safety and also of cost and economic impact," said James May, Director-General of the UK Offshore Operators Association (UKOOA), the body that represents Britain's North Sea oil companies. Bringing a large platform ashore and dismantling it could cost "tens of millions of pounds," Mr May said.
There are 64 such installations in United Kingdom waters, most of which will come to the end of their natural lives between 2010 and 2020.
The Government is actively pressing for the loophole and officials will try and secure it at a three-day preliminary meeting, beginning in London tomorrow, of the OSPAR convention for the protection of the marine environment of the north-east Atlantic.
Britain is supported in its stance by Norway, whose companies own most of the other large steel platforms in the North Sea. However, it is being opposed by the other thirteen parties to the convention, which include Germany, France and most of the countries of western Europe. They argue that what has been installed must be capable of being dismantled and that the techniques are, or soon will be, available.
Brent Spar was the first large North Sea oil installation up for disposal. Shell are proposing turning it into a ferry terminal in a Norwegian fjord.