The entire Netherlands is on a knife's edge this week, holding its breath to see whether a near-mythical ultra ice skating race on frozen canals will become a reality for the first time in 15 years.

Called the Elfstedentocht (Eleven Cities Race), more than 16,000 skaters are expected to brave the canals of northern Friesland province as soon as its organising committee gives the green light that ice conditions are safe.

"The Elfstedentocht is an icon of Dutch skating culture," said Dutch ice-skating historian Marnix Koolhaas, who has written several books on the subject.

"The race has become a religion," he told AFP this week.

But the "Race of Races" is dependent on climatic conditions and to add to its mystique, has been run only 15 times since it began in 1909.

The Society for the Frisian Elf Steden (Eleven Cities), which organises the race told eager journalists at a press conference, broadcast live on national television Monday -- its first since 1997 -- that conditions "looked good".

But chairman Wiebe Wieling added : "At this point we cannot set a date. It all depends on the weather."

"Although we have excellent quality ice in northern Friesland, there is a problem area in the south -- the ice is simply too thin," Wieling said in the northern city of Leeuwarden, the race's start and finishing point.

To stage it, the ice needs to be at least 15 centimetres (6 inches) thick along the entire route to guarantee skaters' safety.

Since Monday an army of Frisian volunteers have been hard at work. Armed with shovels and brooms they have been clearing snow, which hinders ice formation, from the canals on the 200-kilometre (120-mile) route.

"This race is so popular that if you ask the Frisians to help, they'll be there," Wieling told AFP.

"It takes about 10,000 volunteers on race day -- and there are never any problems to find them."

Elfstedentocht-fever has gripped the country, with several professional Dutch speed skaters already saying they would give the Allround world championships in Moscow a miss if the Elfstedentocht was held on the same dates, 18 or 19 February.

Dutch extreme right Freedom Party leader Geert Wilders has called on Dutch Premier Mark Rutte to declare race day a public holiday "so everybody could enjoy it."

In Friesland, hotels are sold out, despite the fact the race may not even take place, Wieling said.

If it does, organisers will give 48-hours notice that it's on.

Skaters leave the start at 5.15 am (0415 GMT) on race day and must return before midnight to receive the coveted Elfstedentocht cross.

The record is held by skate legend Evert van Benthem, who won in 1985 with a time of 6 hours, 47 minutes and retained the title the following year.

Tales of hardship, frozen limbs and frostbite strengthen the race's romance.

"The hell of 1963", a movie released in 2009, tells the story of the toughest race so far, when only 69 of almost 10,000 racers finished in brutal conditions.

In the the Skating Museum in the Frisian town of Hindeloopen, an amputated toe from one of the contestants who got frostbite in 1963 still bears testimony to its extreme nature.

"The tradition began in the 16th century when metal ice skates started to develop," said skate historian Koolhaas.

"Since this is a water-rich area, skating became an efficient way of transport in winter to quickly link Friesland's cities.

A century later, after the Reformation, which deprived Dutch Protestants of carnival, the ice quickly became "the place were anything was permitted."

"On the ice, everybody was equal," Koolhaas added.

In 1986, crown prince Willem-Alexander, then 18, skated the race.

Exhausted, he collapsed into the arms of his mother Queen Beatrix at the finish line.