Wetherill, who lives in Plymouth but grew up in Torpoint, said setting a new record would be great, but he also wanted to inspire others.

"It's never really about breaking records, it's what those actually mean and the wider purpose behind them," he said.

"If we can use this as a conduit to show people what's possible and raise some money, then that is the dream essentially."

He ran his first marathon in Barcelona last year, registering an unofficial time of 5 hours and 44 minutes, which would have broken the existing record.

Wetherill said completing a marathon on crutches with his condition meant he had to battle through what he described as a "pain cave".

"My hip is actually dangling out of its joint at the moment and I'm in pain whether I'm lying in bed or running marathons so my philosophy is I may as well run a marathon," he said.

Wetherill said living as an elite athlete and training like an "absolute animal" had improved his mental resilience over the years and he felt prepared to take on any challenge.

"I've been in situations in my life where I've felt quite helpless and I've felt in despair - I've felt like I can't do things," he said.

"Growing up with a disability, inherently you have those times, and it's not always easy, and I think that's why I'm so addicted to now pushing myself.

"I've not just got off the sofa and decided to run a marathon, I've almost been training for this my whole life."

The London Marathon is on 27 April.