Hindu groups are launching an international campaign today to halt India’s plans to create a shipping channel by dredging the sea between India and Sri Lanka.

They say that the project will destroy an ancient chain of shoals known as Adam’s Bridge, which Hindus believe was built by an army of monkeys to allow Lord Rama to cross to Lanka to rescue his abducted wife. They are also protesting on environmental grounds, arguing that the 30-mile string of limestone shoals, also known as Ram Sethu, protected large parts of India from the 2004 tsunami.

“The bridge is as holy to Hindus as the Wailing Wall is to the Jews, the Vatican to Catholics, Bodh Gaya to Buddhists and Mecca to Muslims,” said Kusum Vyas, president and founder of Esha Vasyam, a US Hindu environmental lobbying group. “It is an unacceptable breach of the religious rights of over one billion Hindus to destroy such a sacred landmark without even consulting us.”

The £280 million Sethusa-mudram project has been mired in controversy ever since it was inaugurated by Manmohan Singh, the Prime Minister, in July 2005. The Government says that the 167km (104mile) channel through the Palk Strait will cut an estimated 400km (and 30 hours) off the journey between the east and west coast of India. The fastest current route is around Sri Lanka.

It argues that Adam’s Bridge is a natural geological formation and that its plans to dredge to a depth of 12 metres will not cause serious environmental damage. It also says that the plan will benefit millions of people in the area by allowing the development of a commercial fishing industry. The project is due to be completed next year, by which time an estimated 48 million cubic metres of silt will have been removed from the Palk Strait.

However, Hindu leaders appear determined to thwart those plans. In a rare show of unity, they are urging Hindus across the world to protest to Sonia Gandhi, leader of the ruling Congress party, to the Indian Minister for Shipping and to Indian embassies in Britain and the US. They are also planning protest marches near the site as well as demonstrations around the world. Ranbir Singh, the chairman of Hindu Human Rights, said: “The Government of India is entitled to take care of the country’s trade and commercial interests, but not at the cost of destroying a site that is revered by one billion Hindus in the world.”

Ramesh Kallidai, secretary general of the Hindu Forum of Britain, called for a posttsunami consultation to assess the environmental impact in the light of new data.

Central to the controversy is the question of whether Adam’s Bridge is man-made or a natural formation. The bridge is believed by some to have been passable on foot as recently as the 15th century. According to Hindu belief set out in the epic poem the Ramayana, it was built about 3,500 years ago. Its purpose was to allow Lord Rama, one of the great kings of ancient India and an avatar of the god Vishnu, to travel from India to Sri Lanka, where he defeated the demonic tyrant Ravana and rescued his wife, Sita.

In 2002, Hindu nationalists cited Nasa satellite photographs of the shoals as evidence that the events described in the Ramayana really took place, although Nasa has distanced itself from those claims.

This month a panel of Indian scientists concluded that the bridge was “a geological formation, which took place about 17 million years ago”.

They could not, however, explain a mysterious series of accidents which have stalled work. First, the dredging vessel Duck6sank. It was replaced by the Dredging Corporation of India’s biggest dredging vessel, but its spud broke. Another ship was then sent to retrieve the spud, but its crane snapped and crashed into the sea.

At least one Hindu leader has suggested that the bridge is being protected by Lord Hanuman, the Hindu monkey god.

Rama and Sita: a love story

— Rama, heir to the ancient Hindu throne of Ayodhya, is sent into exile with his wife, Sita, and brother Lakshmana

— Ravana, the demon king, kidnaps Sita in the woods while the brothers are hunting, and takes her to the island of Lanka Rama, unable to cross the ocean, sends Hanuman the monkey king to find Sita but she refuses to leave unless Rama comes for her

— Hanuman rallies his monkeys to cast stones into the sea and form a bridge to Lanka

— Tiny palm squirrels help by carrying pebbles to the waters edge and Rama, touched by their efforts, stroked one, marking it with the stripes — hence giving the five-striped palm squirrels their name

— Rama crossed the bridge with the monkey army in tow to do battle with Ravana’s demon army. Ravana is killed

— Sita and Rama are reunited but Rama refuses to take her back as his wife. To prove her purity, she walks through a funeral pyre and emerges intact. The pair return to Ayodhya to take the throne.

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