We will fight them on the beaches ...

Next week, Greece faces an unprecedented embarrassment over the beaches of Zakynthos, southernmost of the Ionian Islands, which attract a quarter of a million holiday-making Britons each year.

Unless it acts before 22 January, the Greek government will be arraigned for breaches of the Bern Convention on the Conservation of European Wildlife and Natural Habitats. The Council of Europe alleges that Greece has failed to protect the interests of the other visitors to Zakynthos. Each year, an average of 800 loggerhead turtles come to nest on the 10km of sand that ring Laganas Bay. The turtles are an endangered species and the beaches are a breeding site unique in Europe.

In the latest twist of a 15-year struggle to control Laganas Bay, if the Greek government does not protect the turtles' nesting beaches, under Article 18 of the Bern Convention, the Council of Europe will appoint an outside arbiter to determine how the beaches should be run and managed. No conservation case has ever been put to arbitration before.

Zakynthos is the glorious, wish-you-were-here setting for one of the nastiest ecological battles in Europe. A coalition of Greek conservation groups is campaigning to get Laganas Bay declared a national marine park. Should that happen, many seafront traders will lose their livelihoods. In the face of mounting pressure from the Council of Europe and, belatedly, from the Greek government, the political tide is turning against the profiteers.

After Libya, Zakynthos plays host to the largest breeding population of loggerhead turtles in the Mediterranean. They come for the sheltered waters, hot sun, soft sands and gentle slope - exactly what we look for when we flick through the brochures in our local travel agent. But turtles like their beaches quiet. The noise and paraphernalia of a contemporary Mediterranean holiday are incompatible with their reproductive needs. Parasol spikes destroy nests, disco lights disorient the hatchlings and speedboats kill the adults.

Environmentalists took up the sea turtles' cause in the early Eighties and met with fierce opposition from some locals. They lit night-time bonfires on the beaches, took pot-shots at those who sought to protect the turtles, and have been threatening, beating and burning ever since.

In 1986 the case came before the Council of Europe's Conservation Standing Committee and has been raised at every subsequent meeting. The loggerhead turtle is listed as endangered under the Bern Convention. This puts a duty on European states to protect it, yet the Greek authorities have been reluctant to intervene. A series of protective measures were enacted but the political will to enforce them was lacking.

"Most Greeks are in favour of conservation," says Lily Venizelos, president of Medasset (Mediterranean Association to Save the Sea Turtle), "but the government can't afford to upset the Zakynthians. The turtles have become a political football."

The task of turtle protection fell to others. Daniel Caute and Caroline Harris are unpaid volunteers for the Sea Turtle Protection Society of Greece (STPS). They spend their summers scanning the sands for potential turtle hazards, advising unsuspecting tourists on turtle protection and smoothing out the remains of the previous day's sandcastles.

Their patch is Gerakas Beach, a middle-class holiday destination where the tourists respond positively to their approaches. The toughest part of the job is negotiating with the men who control the illegal beach parasols. As no one is willing or able to remove them, Daniel and Caroline have to work with the parasol vendors to secure the turtles' best interests. Some vendors are more accommodating than others, but only so far as it does not harm business.

Despite spending so much time on the beaches, Daniel and Caroline rarely see live turtles. All the real action happens at night while the beaches are out of bounds. When on land, female turtles are sensitive to the least disturbance. Caroline recalled a clear, moonlit night when she watched an egg-laying turtle from the cliffs above. Then a courting couple walked along the beach and the turtle abandoned her mission. "She just freaked out," says Caroline.

But the STPS and other pressure groups have at last begun to halt the decline in turtle numbers. On nearby Daphni Beach, where volunteers were stoned the year before, the illegal tavernas have been closed with a consequent doubling in nests. A new, six-knot speed restriction on power boats has effectively stopped watersports in Laganas Bay. And the ban on night flights into Kalamaki airport is enforced so rigidly that in June a planeload of Britons was delayed for 24 hours at Manchester. As a result, 1995 recorded the highest number of turtle nests for many years.

Then one evening in late September, a few hours after the last British tourists had vacated the illegal sunbeds on Laganas Bay, a bomb ripped through the offices of Nikos Lykouresis's architectural practice. Mr Lykouresis is a founder member of the Zakynthian Ecological Movement and his offices double as their headquarters. However, he is unworried by the the violence. "I'm too old for that," he says.

The conservationists believe that ultimately they are winning. Dimitrios Dimopoulos, field co-ordinator for the STPS, believes the forces in favour of the national marine park are now unstoppable.

The Greek Minister of the Environment has finally declared that there will be a park, regardless of the political cost. But last year, for the first time, the local prefecture was elected rather than appointed and elected prefects have proved more reluctant than appointed ones to rock the political boat. The government proposals for a marine park have been countered by another from the Laganas Bay communities, and by a third from environmental groups. The result has been further delays. The Prefectural Council decided on 1 October not to adopt the government plan but to undertake its own management study.

Outside intervention now seems inevitable. The Council of Europe is becoming increasingly nervous that failure to protect the turtles is making a mockery of the Bern Convention. In 1986, the Standing Committee asked for the buildings and tavernas on Daphni Beach to be demolished. They still stand today, nine years after the committee's first request.

The conservationists are already gearing up for arbitration. Lily Venizelos has a team of international lawyers on standby to ensure that Greece honours its obligations. "If I didn't think we could do it," she says, "I'd pack up, go home and be a good grandmother."