He has faced some tough opponents during his career in the ring.

But Southampton boxer Chris Hobbs encountered an equally formidable foe – huge hills – after vowing to help a toddler who needs a £50,000 operation.

Despite being in peak condition, Chris was left exhausted by a gruelling 350-mile cycle ride from Southampton to Scotland.

Chris and his brother-in-law Adam Sullivan took four days to ride from Hoglands Park to Gretna and then faced another uphill task – scaling Britain’s highest mountain.

But the two men are celebrating today after raising more than £2,500 for an appeal launched by the family of two-year-old James Mills.

James, of Hythe, was born with cerebral palsy and is unable to take a single step without help.

He needs a procedure known as selective dorsal rhizotomy, which can boost mobility by cutting the faulty nerves responsible for muscle rigidity.

But the life-changing operation is not available on the NHS, which means that James’s family must fund the surgery themselves.

Chris and Adam decided to back the appeal by cycling to Scotland and then trekking to the top of 4,409ft Ben Nevis.

Chris, 26, of Sholing, said: “It was very hard on the legs but we pushed through and completed the challenge.”

The two men reached the top of Ben Nevis in less than three hours, but Adam suffered a knee injury, which meant that it took them four hours to get down again before they faced a nine-hour drive back to Southampton.

Chris added: “We’ve already raised more than £2,500 and more money is coming in.”