A nine-year-old boy is set to walk through central London for 12 hours overnight to raise money for a children’s hospital.

Barney Thomas, from Bristol, will be accompanied by his father Darren Thomas, 36, and his godfather Bradley Hackett, also 36, as they tackle what they are calling a “midnight march” around the UK’s capital.

The trio, who have taken on three fundraising challenges in the past, are raising money to provide play and gaming equipment for Bristol Royal Hospital for Children after Barney was born with two holes in his heart.

He had a “life-saving” operation when he was 11 months old and has continued to give back to the hospital with his charitable efforts.

Barney standing with his father Darren and his godfather Bradley in front of a river
Barney will be accompanied by his father Darren Thomas (left) and his godfather Bradley Hackett (right) in his upcoming challenge (Darren Thomas/PA)

“I’m nervous and excited, and I reckon the hardest part will be staying awake,” Barney told the PA news agency.

“I had two holes in my heart when I was a baby and they (Bristol Royal Hospital for Children) gave me a life-saving operation.”

Their upcoming challenge will see them set off from London’s Paddington station at 6pm on December 22, walking to iconic spots such as Wembley, Big Ben, The Shard, Tower Bridge and Brick Lane, before returning to the station at 6am to catch the first train home on December 23.

Mr Thomas, an operations manager for Network Rail, told PA: “I’m really proud that I’ve got a little boy that cares.

“He takes great pride in his fundraising and we always look forward to the day together.”

Barney and Darren surfing in Cornwall
Barney and his father Darren Thomas surfing in Cornwall (Darren Thomas/PA)

To prepare for the challenge, Barney said he will be staying up all night on December 21 and then sleeping throughout the day on December 22.

When asked what will motivate him, Barney said he will “put some Oasis on”, with Mr Thomas adding: “He loves Liam Gallagher.”

Mr Thomas said Barney was one-month-old when two holes were detected in his heart.

He had an operation to seal them 10 months later, with Mr Thomas saying that Barney “woke up straight away” after the procedure.

Barney as a baby lying in a cot
Barney was born with two holes in his heart and had a ‘life-saving’ operation when he was 11 months old (Darren Thomas/PA)

“It was as if somebody flicked a switch, his face was red and he ate a whole Twister ice lolly – he was really happy,” he said.

“We were really grateful to the children’s hospital and the charities that work in conjunction with them.”

To find out more information, visit Barney’s fundraising page at justgiving.com/crowdfunding/barneysmidnightmarch