David Walliams on his Sport Relief Thames swim challenge

Comedian David Walliams is swimming the length of the Thames for Sport Relief.

The Little Britain star will swim the 140 miles (225km) from Lechlade in Gloucestershire to Big Ben in London in eight days, starting on 5 September.

It is being described as his most dangerous and gruelling challenge to date and is the equivalent of swimming the English Channel seven times.

He spoke to BBC Breakfast and explained how he will be going about the swim.