While the party that won 2.3 million votes in the 1989 Euro elections slides towards extinction (it no longer even figures in most opinion polls), the three are being reincarnated as what they call "a very different kind of environmental organisation".
At a Westminster hotel, Jonathon Porritt, Sara Parkin and Paul Ekins are to launch Forum for the Future as "a megaphone for good news". It will concentrate on promoting solutions rather than publicising problems, pioneering new green economics, setting up a database of best environmental practice, and running a scholarship programme for "future leaders".
The pounds 180-a-night, three-restaurant St James Court Hotel - built around a courtyard with a fountain and ornamental trees - is a far cry from the Green Party's favourite conference centre at Wolverhampton's forbidding town hall, and from the tepees of some of its leading members. And the trio's new supporters are rather different from such former colleagues as David ("I thank God I am a loony") Icke and veteran hippie Sid Rawle.
They have the backing of a formidable assembly of the great, the good and the green (though perhaps not invariably all three at once). Their Council, chaired by the film producer Sir David Puttnam, includes Richard Branson and Glenys Kinnock, Chris Patten and actress Juliet Stevenson, Michael Grade, chief executive of Channel 4, and Will Hutton, author of the bestselling The State We're In. Rock star Peter Gabriel will also sit on the Council, with Sir Crispin Tickell, former ambassador to the UN and chairman of the Prime Minister's special advisers on the environment; author Douglas Adams will rub shoulders with Sir Ghillean Prance, director of Kew Gardens, and percussionist Evelyn Glennie with pollster Robert Worcester. There is even a - rather less exalted - place for Mrs Thatcher's favourite PR, Sir Tim Bell, who will serve on the forum's "Development Board".
The three are surprisingly coy about their Green Party past - only Sara Parkin's association is listed in the organisation's Business Plan. But, to be fair, they have all come a long way since then.
Jonathon Porritt, the former teacher who chaired the party in 1979-80, went on to become director of Friends of the Earth, overseeing rapid growth in the organisation, and is probably Britain's best-known environmentalist. Paul Ekins, a former opera singer who also chaired the party, is now one of Europe's most respected green economists. And Sara Parkin, the former nurse who was chiefly responsible for the party's electoral success, is heavily in demand as a lecturer to such as Nato.
The three met and became friends while with the party, launched futile bids to reform it and make it electable, and - says Ms Parkin - conceived the idea of the forum partly out of their frustration. To an extent it is a vehicle for what three forceful individuals want to do, though they are keen to make it more than the sum of its component parts.
Some of its most important work will be on Mr Ekins's economics, including an Ecological Tax Reform which proposes shifting the burden of taxation from labour (which aggravates unemployment) to energy and other resources (thus cutting waste and pollution).
The group will carry out consultancy work to supplement the pounds 500,000 they have raised so far - from such bodies as the World Wide Fund for Nature and the Duke of Westminster's Trust - to finance the forum. It has recruited "Corporate Partners" with "a proven commitment to environmental issues" including B & Q, the National Westminster Bank, the Body Shop and - rather more improbably - Tesco, the Post Office and Wessex Water. And it is working with Keele University to set up its database of best practice.
"People have a very negative mindset about the environment," says Mr Porritt. "They do not feel excited about it. The forum will be the institutional champion of all the champions already out there delivering the solutions in companies, local authorities, community groups, voluntary organisations, quangos - even government departments."Reuse content