An accountant plans to complete seven marathons in seven days in a bid to raise £50,000 for charity after losing two colleagues to cancer.

Jon O'Shea, 45, partner of Haslers Chartered Accountants in Loughton, will complete seven full marathons in Chile, Miami, Madrid, Morocco, Dubai and Antarctica where he will face temperatures as low as -25C.

The accountant will be travelling 24,000 miles around the world whilst experiencing and average temperature change of 50 degrees.

He will also be living on of airplane food as he aims to complete the challenge in less than 168 hours.

Mr O'Shea plans to raise £50,000 that he will donate between charities St Clare Hospice and Teenage Cancer Trust as well as local charities and causes that the Haslers Foundation have supported over the years.

In a bid to beat fatigue, jet lag and sleep deprivation, Jon has been undergoing an intense training regime which includes completing four other marathons in Russia, South America, Chelmsford and London before he takes the challenge on January 17.

Mr O'Shea said: "In the last two years we have lost our former Chairman, Martin Anderson, and also our youngest employee, Charlotte James, to the curse that is cancer and I will do this challenge in their memories.

"I am only going to do this once, so now is the time to make a real difference to these incredible charities.

"I hope with the support of the public I can raise close to my £50,000 target."