Michael Palin and Terry Jones got Hampstead Heath hopping as they led a madcap world record attempt based on one of their classic sketches.

Hordes of plucky comedy fans took to one leg for the 400m “hopathon” at the Parliament Hill running track, in a bid to set the first ever world record for hopping on Saturday (March 3).

It was inspired by the Monty Python pair’s 1970s comedy series Ripping Yarns, which featured the original hopathon, a 30-mile race between two boys’ schools.

After a few stretches and a stern warning that switching limbs would not be tolerated – “No swapping your leg with somebody else’s” Palin said – a foghorn sounded and the hoppers were off.

Fellow Python Jones, 70, who lives in Highgate, said: “It’s the most rewarding moment in my life to see this, 35 years after we wrote the sketch. We discovered just how hard hopping is when we filmed it, so I’m full of respect for everyone here.”

The field quickly spread out as smiles became grimaces and what seemed like harmless fun turned into a true test of grit and determination.

They were spurred on by the cheers of Palin and Jones, who did not take part.

Yet despite their heroic efforts, the hoppers did not leap into the record books after only 100 crossed the finishing line. Guinness World Records required 250 to go the distance to recognise the feat.

But Palin, 68, who lives in Gospel Oak, said: “They have gone well beyond the call of duty. It was meant to be a punishment in the original sketch, and so many turned up to be punished, it’s just fantastic.

“It should be an Olympic sport – and anybody who got to the end deserves a medal.”

The event was staged to mark the DVD reissue of Ripping Yarns on Monday (March 5).

The organisers had brought in three first-aiders to attend to sprains or strains and an independent lawyer to verify results – and many of the hoppers had taken matters equally seriously.

Town planner Brendan Hodges, 45, of Park Hill Walk, described his training regime: “I marked out an eight metre course using chairs in my garden and hopped around it 50 times. I did it twice – 10 minutes 45 seconds is my personal best.”

Fellow Ripping Yarns fan David Miller, 26, of Stratford, who works at an Inns of Court, was also prepared.

“I’ve done some standing on one leg to try to strengthen the muscles,” he said.

In the event, 37-year-old Ben Langley from Golders Green was first across the line in the main race, and Palin and Jones will be donating �500 to his chosen charity, The Stroke Association.

A 4x100metre relay record bid also ended in honourable failure as the winning team made it round in two minutes and 12 seconds – but failed to crack the daunting one minute and 10 seconds benchmark set by Guinness.

The team split their �500 donation between four charities.