The battle for St Helena

Diana's Peak, the verdant summit of a long dead volcano, was the first thing Napoleon would have seen of his new island home as he sailed towards it 190 years ago.

Rising 800 metres out of the Atlantic Ocean, St Helena's rocky peak is the highest point of one of the remotest islands in the world, and is the only landfall for 700 miles in any direction.

To the French emperor - who had hoped for exile in England after losing the Battle of Waterloo - it must have resembled a tombstone, as he contemplated the last port of call he would make in his life.

Napoleon's imprisonment in 1815 and his death six years later gifted St Helena its place in history and cemented the island in the popular imagination as a byword for isolation.

But the British Government has had a belated change of heart over its remotest prison colony and is seeking to turn the outpost of Empire into a modern-day paradise island, fit for five-star tourists. Pitted against them is an alliance of conservationists concerned the island's unique biodiversity will be sacrificed in pursuit of a development model heavy on golf courses and jet-liners but light on environmental planning.

On one side is the Government's Department for International Development, determined to bring mass tourism to the tiny, beautiful but very broke South Atlantic island by building, at taxpayers' expense, an international airport, equivalent in size to Birmingham International, on one of St Helena's most environmentally sensitive areas.

Pitted against Whitehall are conservationists, historians and many islanders, fearing St Helena's already precarious wealth of indigenous plants and wildlife, and its exceptionally rare and largely untouched historic buildings dating from Napoleon's time, will soon be lost in the Government's push for mass tourist cash.

St Helena, a mountainous volcanic outcrop just 10 miles by six, has always been celebrated for its remoteness. It is 1,200 miles from Africa, 1,800 miles from South America and 700 miles from Ascension Island, the next nearest land. The island is the deeply eroded summit of a composite volcano, which lends St Helena its extraordinarily dramatic topography.

Plugs, domes, and dykes from the volcanoes create striking formations with names such as Lot, Lot's Wife, and the Gates of Chaos. Its coastal cliffs thrust 300 metres out of the sea and its narrow land mass is cut by a few steep-sided valleys. The climate is dry subtropical, ranging from 15°C to 32°C, with an annual mean rainfall of 152mm.

Discovered by Portuguese sailors in 1502 and British-owned since the 17th century, it is still only reached by sea once a month from Cape Town by Britain's last Royal Mail ship, the RMS St Helena. St Helenians were last honoured by a British ministerial visit in 1699.

Long in decline, with no industry or resources and a dwindling population, the island receives more than £13m a year in support from the Government, making its citizens among the most heavily subsidised of the UK dependants. They are also to receive a further £10m from the EU for infrastructure improvement.

With a population of about 3,800, St Helenians - or "Saints" - are among the most subsidised people in the world. The island has no political parties, no trade unions, and a recent crime wave consisted of the theft of one computer and a man caught relieving himself against a wall. But it is rich in flora and fauna and exceptionally important historic buildings.

The new airport is to open in 2010, when the RMS St Helena will be retired. Working with Whitehall, the local St Helena Leisure Corporation (Shelco) has come up with a series of proposals including luxury hotels and a golf course to lure tourists.

Behind Shelco is the international hotel group Oberoi Hotels and Resorts, which operates a series of luxury sites stretching from Melbourne to Mauritius.

Dr Rebecca Cairns-Wicks, a leading St Helena expert and conservation biologist, who lives on the island, is concerned that funding is not being given to the right projects. She said: "There are incredibly rare trees and flora on this island.Plants extinct elsewhere have survived. Some of the most endangered flora in the world is here.

St Helena has already been the victim of one man-made environmental disaster as large barren and eroded areas of the island known today as the "Crown Wastes" bear testament.

Naturally colonised millions of years ago, the island became a refuge for its own unique species as well as for flora and fauna that later disappeared from mainland Africa.

Human exploitation of the island's natural resources for more than 450 years has led to the degradation and erosion of large areas of land. It is considered to be one of the first documented environmental disasters instigated by humans.

A revival of interest in conservation of endemic species in the 1970s has seen some small amount of progress being made in recovering St. Helena's lost habitat. But that could all be swept away by insensitive development.

Dr Cairns-Wicks said: "There's the false gumwood tree - we're down to the last eight plants in the wild on the island. The St Helena wild olive vanished recently - the last single tree died. We have only one surviving variety of land bird, the St Helena Wirebird, and it's down to only about 400."

The Wirebird, a distinct race of Kittlitz's Sand Plover, has drawn birdwatchers from all over the world, prepared to brave the month-long round journey to see it. A land bird- whose long thin legs gave it its name - it flies only when necessary and its key habitat is right in the flightpath of the new project.

The runway - at 2.5km, it is intended to take large Boeing 737 and Airbus A320 planes - is of particular concern to environmentalists. The chosen site, Prosperous Bay Plain, is itself an area of exceptional interest. In a report, lodged with UK authorities last year, Atkins Management Consultants warned that the site at Prosperous Bay Plain was a "hotspot" of endemic invertebrates deserving of rigorous protection and international recognition.

"At least 20 invertebrate species identified from Prosperous Bay Plain are reported to occur nowhere else in the world," the report states.

"It's a hotspot for rare invertebrates such as species of scorpions and spiders," said Dr Cairns-Wicks. "It's a mini-desert eco-system, totally unique. It's not like you can recreate this when it's gone." Much of St Helena's well-preserved heritage is already vanishing, the victim of neglect, termites and "restoration".

Martin Drury, a former head of the National Trust and one of the most respected figures in world conservation, has joined the fray. He condemned the Government's plans for a major international airport on St Helena - projected to cost at least £40m - and the inevitable expansion in mass tourism.

Mr Drury is angry at Britain's treatment of what he sees as a neglected gem. "The historic buildings there are of a very high quality," he said. "There's nothing I've seen around the world that equals it. In the main town, Jamestown, there's a complete repertoire of a Georgian colonial settlement.

"The whole character of St Helena is one of simplicity, and that is absolutely not what tourist operators understand. It's a matter of regret to have an international-scale airport. It's mad." The island has now launched its own National Trust.

The trust has sent out a message-in-a-bottle-like plea, via the pages of the UK architecture magazine Cornerstone, published by the Society for the Protection of Ancient Buildings, for specialists to come and save St Helena's crumbling colonial villas and forts.

The DfiD has refused to comment on the final cost of the airport, and insisted that "Saints" had been fully consulted before a decision was made over the airport construction.

A department spokesman, Yasser Mehmood, said the airport plan had been endorsed by more than 70 per cent of voters in a 2002 poll. What DfiD neglected to point out was that turnout for that poll - organised by the St Helena government, included voters on Ascension Island and even the Falkland Islands.

On St Helena itself, locals' deep ambivalence was shown by a less than 50 per cent turnout, where just 909 votes were cast in favour - about 30 per cent of the potential electorate. No one is pretending that St Helena isn't set to change. A department spokesman admitted that: "To the extent that travel to and from the island will no longer exclusively be by sea," he said, "that part of its character which derives from its reliance on sea access inevitably will change." In an increasingly globalised world it could be the very quality of isolation that defined St Helena's first 500 years of habitation, which proves its undoing.

For conservationists, the construction of an airport presents an unprecedented threat.

The glimpse of the isolated history that St Helena offers the visitor today is sure to be swept away in the rush.

For Mr Drury it will be a sad ending for a piece of living history: "The forts and batteries are extraordinary because they've just been left. The British guns are there. If you scratch around you can find soldiers' buttons in the dust."