A British man running the length of Africa has set off on his final day of the gruelling challenge in Tunisia.

Russ Cook, who calls himself “Hardest Geezer” on social media, has been running for more than 350 days and completed the equivalent of 385 marathons.

The 26-year-old, from Worthing, West Sussex, is now running the final 40km of the 16,000km challenge and has been joined by hundreds of supporters.

“One more day, one final push to get this thing done,” he said to Sky News shortly after setting off, with sports correspondent Rob Harris trying to keep up.

He says he will become the first person to run the full of length of Africa if he completes the challenge.

Mr Cook has been raising money for two charities along the way and has recently seen a surge in donations.

In the last seven days, he has raised more than £217,000 of his £568,000 total.

He is fundraising for The Running Charity, which supports the mental health of young people with complex needs or who are homeless, and Sandblast which educates people about Sahrawi culture.

Although the run across Africa is his biggest challenge, it isn’t his first.

At 22, Mr Cook ran from Asia to England, completing 71 marathons in 66 days.

He had only run the Brighton Marathon before he decided to run from Asia to England.