A sea of Santa Clauses pulled on their running boots and pom-pom hats for a charity dash in London to raise money for a leading children’s hospital.

The course at Clapham Common resembled a Christmas convention as about 3000 Santas, and many festively dressed dogs, ran in support of Great Ormond Street Hospital (Gosh) on Sunday.

Among those in red was TV presenter and former Strictly Come Dancing winner Ore Oduba, who revved up the runners and met families and Gosh patients.

“It’s genuinely something I’ve never seen before and one of the sights of my year,” he said of the thousands of Santas.

Oduba, who said this Christmas will be special for him as he recently had a son, was proud to support the “amazing” fundraising cause for Gosh and its patients.

“We’re talking about families who are going through one of the most difficult times of their life, especially around Christmas time,” he said.

“To have all these people here raising as much funds as they can, bringing families together and helping them get through this time is an amazing thing to be part of.”

The runners included inspirational three-year-old Esme Hughes, from Reading, who only months ago had a heart transplant at Gosh.

Her father Kevin said Esme, born with aortic stenosis, stayed at Gosh for a year but she was now happily on her feet.

“She had a heart transplant a few months back. As you can see, she’s doing quite well,” he said as Esme walked beside him.

Also running was Jasper Sherlock, three, who had a bleed on his brain hours after birth and survived after a number of surgeries at Gosh.

“They saved his life and they continue to help him,” his mother Gemma said.

“It is an unbelievable place.

“We spend a lot of time at different hospitals but Great Ormond Street is unique.”

She said Jasper was a “sociable” and friendly boy who liked horse riding and has recently tried skiing.

Jasper’s family, from Hampstead in London, was taking part in the dash for the third time and together they have raised some £20,000 for Gosh.

The Santas set off in spaced groups although there was still a bit of Christmas congestion along the way given the numbers.

“I’m told there’s a blockage of Santas ahead so take care,” a course controller said through a megaphone.

Every signed-up runner was provided with their own Santa outfit, which included a biodegradable felt Santa hat.

The event is expected to raise about £300,000 for Gosh, helping to fund state of the art medical equipment, research and a major refurbishment of the hospital.

“Every penny raised will make a difference to the hospital,” Gosh’s head of community fundraising Laura Savory said.

As they crossed the finish line after 5km or 10km, runners were showered with a snow cannon before heading home still in their Santa gear.