A 24-stone prison officer from Watford is aiming to lose six stone in 11 months to raise money for a four-year-old with cerebral palsy.

Gary O’Brien, known to friends and family as "Uncle Buck", has decided to combine his weight loss resolution with a fundraising venture for Jake Skinner, a boy in the nursery class at Orchard Primary School, Gammons Lane, attended by Mr O'Brien's son.

Jake was born with cerebral palsy which causes spasticity in his legs, making moving around and walking difficult. His family have been fundraising for the last two years so that he can go to the US for an operation. They managed to raise enough to take him in October last year and the operation was deemed a great success with doctor predicting him to be walking unaided within two years.

Jake's family are now fundraising for him to have the aftercare needed to get the full benefit from the operation.

Mr O’Brien said: "I've set a target of trying to raise five thousand pounds and that will take Jake to the goal target. Jake is such an adorable lad and is in the same class as my son, William, at nursery. I made my mind up to do the fundraising when after watching my son’s Christmas concert.

"All the class were dancing around the Christmas tree and Jake was just sitting on the floor dressed as a Christmas pudding and watching. My heart melted and I'm so motivated to do this for him."

The 42-year-old has been given 100/1 odds with William Hill to lose the weight and has placed a bet on himself. Orchard Primary School is also showing their support and using Mr O'Brien's weight loss attempts to create a "Keep Fit" campaign for the students.

The prison officer will have to go for weekly weigh-ins at the school and he said "if I don't manage it now, I think I'll have to emigrate".

Mr O'Brien said: "Seeing the difference between Jake and my son who is the same age really pulls at the heart strings. I think his mum was really pleased when I put the idea to her. They haven’t got much in the pipe line for this year and I’m hoping to reach the target for them. Hopefully this will be good for him and for me. I’m getting a very good response already from friends, family and work colleagues."

To donate, go to http://www.justgiving.com/goodbyeunclebuck