A Norwich man whose marathon dreams were thwarted by a debilitating illness has spoken about why he is determined to make it to the finish line this April.

Jon Kelf is set to run the London marathon for the fifth time in 10 years on April 22 - but this time it will be his toughest yet after recovery from an operation to remove a tumour linked to rare and incurable auto-immune disease Myasthenia Gravis (MG).

Now 44, Mr Kelf was first diagnosed the disease when he was 28. He underwent an operation and managed to battle back to then go on to run the 2002, 2003, 2005 and 2007 London marathons.

It was when he was training for the 2010 London marathon that the tumour had returned, making his MG symptoms worse.

Instead of running the 26.2 miles on the day of the 2010 London marathon, he found himself in a hospital bed recovering from open chest surgery for the second time.

He said knowing what he has been through over the last two years will make getting to the finish line on the April 22 'so much sweeter'.

Mr Kelf, who lives in Tollhouse Road, near Dereham Road, with his partner Dawn, said: 'Training has been a real struggle and I can run half a mile to a mile then have to walk.

'But however long it takes, I will finish it. I felt as though I should've done it in 2010 and I wanted to do it again this year to get it out of my system and to show that this illness will not beat me.'

Mr Kelf is raising funds for the Myasthenia Gravis Association which is dedicated to finding a cure, raise awareness and help sufferers of the rare illness.

Myasthenia Gravis causes muscle weakness and can make walking up and down stairs difficult. It affects about one in 20,000 people.

To sponsor Mr Kelf, go to http://uk.virginmoneygiving.com/JonKelf.

Are you running the Virgin London Marathon for a cause close to your heart? Call reporter Kate Scotter on 01603 772326 or email kate.scotter@archant.co.uk.