On Wednesday, as he waited for his new boots, Mr Scott passed the 15-mile mark and was still on course to finish by Friday.

It means I'm beginning get quite unstable - which as you can imagine would be a bit dangerous

Lloyd Scott

That would give him the record for the slowest ever London Marathon - at an average speed of four-and-a-half miles a day.

Dressed in his 120lb, antique, deep sea diving suit, he said: "We have been waiting for the new boots to come for a couple of days as the current ones are causing some problems.

"They are wearing away on the heels and at the toes.

"It means I'm beginning get quite unstable - which as you can imagine would be a bit dangerous."

  For a map showing his steady progress, click here.

He said his sister was due to bring the new boots on Wednesday evening, when he should have completed 17 miles.

But he added: "It's a bit of a shame in one way though, as they'll be a bit heavier again."

The father of three is raising money for the charity CLIC - Cancer and Leukaemia in Childhood.

Mr Scott, from Rainham in Essex, was diagnosed with leukaemia in 1987 and ran his first marathon as part of a fitness regime to prepare for a bone marrow transplant two years later.

Lloyd Scott used to play for Watford, Blackpool and Leyton Orient

He has since completed runs across Death Valley and the Sahara Desert, expeditions to the North and South Pole and climbs of Mount Kilimanjaro in Kenya and Mount Aconcagua in Argentina.

Five diners at a restaurant along the route donated a total of �1,000 - and anything on the menu - in return for Mr Scott taking a slight detour to see them.

Mr Scott estimates he has now collected about �6,000 from money thrown into buckets, and will raise up to �100,000 in total.

His family and friends are travelling with him in a mobile home, where he is spending the nights.

He was a professional goalkeeper with Watford, Blackpool and Leyton Orient, before becoming a fireman.

Mr Scott bought the 1940s diving suit for �2,500 and removed the glass to allow him to breathe.

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