THOUSANDS of protesters manned barricades on the French-Italian Alpine border yesterday to stop the construction of a controversial high-speed pan-European railway.

Environmentalists and local residents in the Val di Susa have been campaigning for weeks against the new rail link, known by its Italian initials as TAV. The focus of their protests is the Lyon to Turin stretch, with demonstrators opposing a 53km (33-mile) tunnel from St Jean de Maurienne on the French side to Venaus on the Italian side.

Work on the tunnel, estimated to cost €15 billion (£11 billion), was due to start this week. Yesterday, however, the protesters claimed initial victory after confronting 2,000 riot police in the snow to delay the start of construction.

In Venaus the slogan “No TAV” hangs in banners from every house and is sprayed on walls. Yesterday demonstrators huddled round oil-drum fires in the bitter cold while volunteers distributed minestrone soup.

The project, backed by the European Union, also involves a secondary 21km tunnel through Mount Musine, a local landmark. Dubbed “Corridor Five” in EU jargon, the high-speed railway will eventually run from Lisbon to Kiev by way of Barcelona, Lyon, Turin, Trieste and Budapest.

Local residents said that the peace of the Alpine woods and meadows would be destroyed by the 300 goods and passenger trains a day that will thunder through at 150km/h (93mph). There is also fear that the works, expected to last up to 20 years, will cause long-term environmental damage.

For some protesters the focus is Mount Musine, known as the “Magic Mountain” because of its supposed occult powers and magnetic currents.

A cross on the summit, placed there in 1900, recalls the moment in the 4th century when the Emperor Constantine saw a “burning cross in the sky” forecasting his victory over his rival Maxentius, a vision that helped to persuade the Emperor to convert his empire, and hence Europe, to Christianity.

The dark, bare mountain is also associated with Celtic rites, and is the site of frequent alleged UFO sightings. A more practical objection is that tunnelling through the mountain will release both asbestos and uranium, endangering the health both of the workers and local residents.

Silvio Berlusconi’s centre-right Government claims that the TAV is vital if commercial traffic is to be lured from the roads to the railway.

Pietro Lunardi, the Transport Minister, said that trans-Alpine road traffic had risen elevenfold in 25 years. He said that for passengers, the rail trip from Turin to Lyon would be cut from four hours to 90 minutes, with the Turin to Paris run cut to three hours.

“This kind of infrastructure project is essential if we are to make Italy competitive,” Signor Lunardi said.

He said that the Government had begun talks with the protesters last year, to no avail. “Blocking the Turin to Lyon line will cause enormous damage not just to Italy but to the whole of Europe”. Spain and France enjoyed advanced road and rail networks, he said, but Italy lacked both.

The Green Party, which forms part of the centre-left opposition, widely tipped to defeat Signor Berlusconi in April’s election, said that it would seek alternative solutions if the Left came to power.

“There is an existing railway which could simply be upgraded,” a Green spokesman said.