HANOI (AFP) - The task of safeguarding the embalmed corpse of Vietnam's revolutionary leader Ho Chi Minh is gruelling: Carefully selected riflemen work around the clock, watching over the communist nation's founding father who died 50 years ago.

Protecting him is the ultimate patriotic service for men in stiff white uniforms at president Ho's towering tomb in Hanoi, a monolithic shrine to a man who still pervades public life despite his fading relevance among the young.

The job is a "dream come true" for guard Nguyen Xuan Thang, even if it is not always easy.

"We have to have our eyes on everything to deal with any situation that may arise," the 41-year-old lieutenant-colonel told AFP.

All year round, he works up to four two-hour shifts every day - often outside the tomb in the blistering summer heat, monsoon rain, or frigid winter weather.

Some days, he works inside the cool, dark chambers where president Ho's waxy body - his wispy goatee beard still intact - is on display for daily pilgrimages by thousands of schoolchildren, tourists and war veterans who come to pay their respects.

Even after hours, Ho is never alone: soldiers flank his encased body 24 hours a day.

"For us who see him every day, the emotion is still overwhelming," said Mr Thang, who like the rest of his team was hired because of his physical stamina, communist party dedication and easy-on-the-eyes appearance.

Guards like Mr Thang are not the only ones tasked with looking after Uncle Ho, as he is affectionately known in the country.

A team of four Russian and seven Vietnamese scientists were hired this year to evaluate his embalmed corpse ahead of the 50th anniversary on Monday (Sept 2).

"The body of president Ho Chi Minh has been kept in very good shape," said Major-General Cao Dinh Kiem, a senior member of the team in charge of guarding the mausoleum, which opened in 1975.

Rumours abound in Vietnam that the body might not really be Ho, or that he is sent to Russia every year for maintenance, which Maj-Gen Kiem dismissed with a smile.

"In short, that is not correct," he said.

Leaning on Russian embalming expertise is not new in Vietnam.

Ahead of president Ho's death in 1969 - and behind his back - his aides turned to allies in the Soviet Union to ask how they preserved their own communist founding father Vladimir Lenin, who is still entombed in Moscow's Red Square.

Vietnam struck up a deal with the USSR to receive embalming materials and guidance from their experts.

The deal died after the collapse of the Soviet Union in 1991, and Hanoi scrambled to replace it with a commercial arrangement for the exchanges, which remains in place today.

Considered state secrets, the details of that arrangement cannot be publicly shared, not even with communist allies North Korea or China, which have both preserved former leaders for posterity.

"In terms of (sharing) the pharmaceutical techniques, it's an absolute no," said Maj-Gen Kiem.

President Ho did not live long enough to see the end of the bloody war against the United States-backed south in 1975, when North Vietnamese tanks rolled through the former southern capital Saigon, later renamed Ho Chi Minh City.

But he did deliver clear burial plans in his will: a request to be cremated and have his ashes modestly displayed in north, central and south Vietnam in a sign of symbolic unity.

"There should be no stone stele or bronze statue", but rather a small ceramic urn on three tree-lined hills for visitors, he wrote in his will.

However, eager to capitalise on the popularity of the north's communist leader, his aides chose instead to build a grand tomb, drawing inspiration from Russian leader Lenin's mausoleum, the pyramids in Egypt and the Washington Monument.

The powerful symbol of president Ho continues to be commandeered today by Vietnam's communist leaders; his teachings are invoked in school curricula, political and military training, children's books, patriotic songs and on propaganda billboards.

"The Communist party needs Ho and uses Ho whenever and wherever it can... There is a Ho for everyone - children, mothers, cadres, bureaucrats, and soldiers," said Mr Christopher Goscha, author of Vietnam: A New History.

But for Vietnam's booming young population - around half the country is under 30 - president Ho figures as a distant historic character, far removed from the thriving capitalism, ubiquitous social media and yearning for freedom that preoccupies most of the smartphone-obsessed young today.

"Ho has stiff competition and it's only getting more difficult to make him relevant to this younger generation," Mr Goscha told AFP.

But for Ho's dutiful minders, the communist leader remains a central focus.

Mr Thang and his team busily prepared for an official wreath-laying ceremony for president Ho held last Friday, and expects visitor numbers to surge on Monday for the death anniversary, which also happens to be National Day.

"We have prepared our soldiers spiritually and physically to best serve visitors... and pay respects to the president," Mr Thang said.