The industry stalwart will run the gruelling 26 miles through the capital on April 24 to raise money for the Family Holiday Association.
De Vial, who last year completed a 146-mile triathlon for Abta’s LifeLine charitable trust, is aiming to raise £10,000 for the cause.
On his JustGiving page he explained his reasons for undertaking the challenge, he said: “Three million people in the UK live in what even our own government call ’severe material deprivation’ and within that number are hundreds of thousands of children who live in official poverty.
“Many of those children will not experience any sort of holiday or break this year and more than half of them have never been on holiday.
“Please support some of the UK’s most deprived families and their children - the FHA can only help the most serious cases referred to them by care and protection agencies - but with your help they will be able to make an even greater difference.
“Please dig deep and share some of the joy many of us are privileged to enjoy working in our wonderful tourism industry.”
If you would like to donate to John, visit his JustGiving page.
