But the AA man could not stop laughing when he arrived to find the casualty was a 6ft long, 90lb blue piggy bank which had had a mishap as it was being pulled along by two men on a tandem bike.

Steve Hunt, 46, and Gordon McKirdy, 33, were heading from Glasgow to London in a challenge to raise cash for Cancer Research UK when a joint holding the pig on the trailer snapped between Longhorsley and Morpeth, in Northumberland on Thursday.

The pair decided to ring the AA and Mr Milner was called by his operations room which just told him to find a "blue pig, size of a Mini".

When he arrived he said he was in fits of laughter as he winched the forlorn looking blue porker onto his low-loader.

Mr Milner said: "I didn't believe it at first but then our ops centre phoned and explained it was a charity event.

"We couldn't stop laughing as I loaded the pig but, after speaking to Gordon and Steve, I realised that this was one piggy that needed urgent attention so headed straight to the local BT depot for repairs.

"We attracted a lot of interest - one guy overtook us twice as he couldn't believe his eyes."

The patrolman went on: "We always put the member first but this is the first time I've been out to a four-legged one. It has to be the most unusual and amusing call-out I've ever had."

At the depot, technicians fixed the pig's frame with the metal legs from their manager's coffee table, leaving the table top on the floor with a note which said: "You did say to fix it at all costs".

Meanwhile, staff at the nearby Halfords store fixed the tandem's slipping gears.

Mr McKirdy, from Buckhurst Hill, London, said: "It had been a tough day with one of the tyres exploding and then the frame snapped for the third time.

"But when Steve arrived in his AA truck, our spirits lifted - he was absolutely determined to help get us going."

Mr McKirdy and Mr Hunt, from Chippenham, Wiltshire, said their Pig Pull Challenge aims to raise £60,000 by passing though as many cities as possible while on their journey south.

They hope to finish in Richmond Park, London, on July 27.

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