A heroes' charity walk has been organised for the day before a brave boy with cancer celebrates his fourth birthday.

Children’s cancer charity Momentum is holding the fancy dress mile-long walk on Sunday in Nonsuch Park.

Terri Lovis, 35, from Ewell, came up with the idea of the charity walk and a few weeks ago it looked as though her son Ollie only had days to live.

Since then Ollie has rallied, and the family plan to bring him along to the charity walk. His father will dress as Spiderman for the occasion.

Mrs Lovis said: "All the cancer kids are little heroes and it’s Ollie’s fourth birthday on the Monday. We wanted to raise money for Momentum. We thought it would be a nice positive thing to do."

Mrs Lovis said Ollie was diagnosed with cancer at the base of his skull in November 2013 and went to America for proton therapy.

Unfortunately, Ollie later relapsed and the cancer has spread to his spine, legs and hip. The family have spent time at Epsom Hospital and seen Momentum’s work firsthand.

Mrs Lovis said the isolation room used to be very bland while the parent’s room was "dark and tired" and not easy to clean.

She said: "They have done a playroom and a new parents’ room which is really lovely. It’s a little bit of a haven where you can have a cup of tea and make some friends."

Haydon the Womble, who delivered donated presents to Ollie at Christmas, encouraged other mascots and families to take part in the fancy dress walk.

Haydon said: "For this event I would love as many families to attend, but also as many mascots as possible, so this is a call to all mascots please come along and join the party, in celebrating brave young Ollie’s fourth birthday.

"Ollie absolutely adores dinosaurs, and has loved his visits from Alan and his owls, so any owl mascots, or dinosaurs, please, please give up an hour or so of your time and join me for a mile walk."

Dee Besant, from Momentum, said: "All Momentum children and siblings are heroes and to put on this event with the support of the local community walking and dressing up as their own hero's will help raise funds for a Momentum boat on the Thames.

"This boat will provide a respite retreat for families to escape to when travelling far from home is not an option."

She added: "Please feel free to bring a picnic afterwards and join us in the dog free area of Nonsuch Park for entertainment and activities."

Momentum Heroes’ Walk; Sunday, May 17; Nonsuch Park’s London gate entrance, Ewell; Meet at 11am, walk starts at noon; £10 for family up to four, £2.50 per additional family member

To sign up for the walk or volunteer on the day email Sarah@moment-um.org

To make a donation visit www.virginmoneygiving.com/team/MomentumHeroes