Captain Sir Tom Moore | DYLAN MARTINEZ

Prime Minister Boris Johnson was among a host of well-wishers across Britain willing record-breaking fundraiser Captain Tom Moore to pull through after the centenarian was admitted to hospital with COVID-19.

Moore, who raised almost 40 million pounds ($55 million) by walking 100 lengths of his garden during last year's lockdown, was admitted to hospital after testing positive for the virus, his daughter said on Sunday.

"You've inspired the whole nation, and I know we are all wishing you a full recovery," Johnson said on Twitter, adding his thoughts were with Moore and his family.

The World War Two veteran caught the public's imagination in April, just before his 100th birthday, when he was filmed doing his sponsored walk with the help of a walking frame around his garden in the village of Marston Moretaine, north of London.

He hoped to raise 1,000 pounds. Instead, he raised more than 33 million pounds ($45 million) for the National Health Service, broke two Guinness world records, was knighted by Queen Elizabeth, scored a No. 1 single, wrote an autobiography and helped set up a charity.