Maoist guerrillas in threat to Everest jubilee celebrations

As celebrations are planned to mark next year's golden jubilee of Sir Edmund Hillary's ascent of Everest, Maoist guerrillas are poised to attack the mountainside airstrip at Lukla that acts as the gateway to the Khumbu valley and the most popular route to the top of the world.

After a week in which more than 100 soldiers, police and Maoists were shot and killed, the prospect of mountaineers missing out on a party might seem a petty gripe. But Everest is the ultimate icon for Nepal.

If the rebels kill off the trekking route up the Khumbu, an already stricken tourism industry will die with it, threatening the livelihood of thousands of Sherpas, porters and yak drivers dependent on trekking and climbing.

When Hillary and Tenzing Norgay reached the summit of Everest on 29 May 1953, Nepal was just opening its door to the outside world. Now the Himalayan kingdom is descending into a nightmare, with more than 7,000 dead as the Maoist insurrection escalates. King Gyanendra, the reigning monarch, has plunged the country into a constitutional crisis.

The endgame in the so-called "people's war" seems close, just as its beleaguered tourist industry was hoping to get a boost from the Everest anniversary.

If Lukla falls, Everest could still be approached from Tibet but ascents on its southern, Nepal side would cease. This would include the South Col route, pioneered by Hillary and Tenzing and now used by commercial expeditions, and also hard test pieces like the South-west face where Sir Chris Bonington and Doug Scott made their reputations in the 1970s.

Sir Chris said yesterday that he fears for the porters who ply the Khumbu. "The really sad thing is that it is the ordinary Nepali people who will suffer, particularly porters. But that's part of the Maoist tactic – maximum misery to help topple the government."

It is already shaky. King Gyanendra has lost patience with notoriously corrupt and incompetent politicians and has put democracy on hold. Last week Nepal endured a three-day general strike called by the Maoists. The chaotic streets of Kathmandu fell silent. Traders may not support the rebels, but if they want to stay in business the shutters go up.

Maoist influence in the city is growing, with traders obliged to pay protection money. A goldsmith in the New Road shopping district said he was handing over thousands of rupees each month. "They are very polite, they sit and have tea." Asked what the alternative was to the tax, the trader drew a finger across his throat. "Twelve years ago I was marching in the street, happy for democracy. Now the King must save us."

King Gyanendra came to the throne in June 2001, deeply unpopular and suspected by many of plotting the palace massacre that claimed his brother, King Birendra. Today he is regarded by most Nepalis as their best hope.

At Lukla airstrip, hope rests on the army and a high perimeter fence ringed by razor wire. Nervy soldiers fire shots into the night from sandbagged lookout posts, but if and when the guerrillas attack, the jungle-cloaked hillside will offer plenty of cover. A curfew is in force, with armed soldiers occasionally entering lodges to stifle singing and dancing by porters and trekkers.

Tourism is a crucial source of income for Nepal. Visitor numbers have already dropped. The Maoists have always said they intend no harm to tourists but increasingly trekkers are being ambushed and ordered to make a "donation". At the point of a gun or Gurkha khukuri knife, it is hard to refuse. Hold-ups in the Makalu and Mera Peak areas suggest a ransom rate of 4,000 rupees (£33) per trekker or 5,000 rupees (£42) for a climber.

The rebels say they will attack Lukla after the trekking season ends next month. There are, however, rumours of ceasefire talks with the palace.

Mountaineers like Iain Peter, planning an anniversary expedition up the South Col route, are watching anxiously. "We have to hope everybody sees the importance of these events going ahead," he said. "It is vital for the Sherpas who live in the Khumbu, all the porters, and for the economy of Nepal as a whole."