Volunteers on the march to help the fading Cernes Abbas giant stand proud once again

Volunteers have been drafted in to re-chalk the 180ft tall (55m) Cerne Abbas giant, after accusations that he had become the invisible man.

The iconic club-wilding figure emblazoned on a hillside near Dorchester, Dorset was carved into the grass at least 400 years ago.

Covered up: The Cerne Abbas giant, pictured in June 2007 (left) and June 2008 - the carving has faded dramatically due to grass growth and no grazing sheep

But conservationists became concerned the naked figure had disappeared under a mass of grass and weeds, after an unusually wet summer and lack of grazing sheep from local farms.

The well-endowed giant - also known as the Rude Man - is thought to have ancient origins, but is best-known as a fertility symbol.

Childless couples have been known to dance, or even make love on the earthwork to boost their chances of conception.

Teams of 30 recruits will painstakingly dig out the 10cm deep outline - and fill it in with 20 tonnes of new chalk from a local quarry.

In all his glory: The fertility symbol has stood proud for 400 years

Rob Rhodes, a warden for the National Trust, which owns the site, said: 'We will simply dig out the old chalk and replace it with the new chalk.

'This year we have been hit with a double whammy. We normally have about 100 sheep on the hillside which keeps the grass down.

'But this summer we had a problem getting them and so the grass has grown like crazy. And the wet weather has exasperated the problem because that has led to lots of weeds and moss to grow on the outline

'This is pretty much smothering the whole of the giant. He is not completely invisible but is hard to pick out.'

They hope to bring the giant back to its former glory within 10 days. Locals have also rounded up 50 sheep to temporarily graze on the site to keep the grass down.

The giant has been in danger of disappearing before. During World War II it was covered over in brushwood by the Home Guard so German pilots could not use it for navigational purposes.

The symbol has occasionally been hijacked by groups including Homer Simpson, who last year offered the Cerne Abbas man a donut to promote his film

Mr Rhodes yesterday appealed for more volunteers to come forward: He said: 'How many ancient monuments around Britain do people get the chance to help maintain? The giant is on a par with St Paul's Cathedral and Stonehenge.'

Anybody who wants to get involved in the project, which is costing several thousand of pounds, should contact the National Trust for West Dorset.