Capt Tom Moore, the second world war veteran who walked 100 laps of his garden before his 100th birthday to raise money for the NHS, has been hailed as a “one-man fundraising machine” by the Duke of Cambridge. Moore, 99, completed his mission on Thursday, but the amount he has raised has continued to rise, standing at £20m on Friday evening, as his endeavours captured the attention of the nation. Prince William, who has made a personal donation to the JustGiving fundraiser, said in a BBC video interview: “It’s amazing and what I love also is that he’s a 99-year-old war vet. He’s been around a long time, he knows everything and it’s wonderful that everyone has been inspired by his story and his determination. “He’s a one-man fundraising machine and God knows what the final total will be. But good on him, and I hope it keeps going.” In response, Moore said: “It’s absolutely amazing that my super prince can say something like that.” He added it was a moment he would never forget. More than 880,000 people have made donations to his fundraising page, and nearly half a million people signed a petition to the honours committee calling for Moore to be knighted. Moore’s fundraising has not stopped with the end of his walk. He has now released a cover version of You’ll Never Walk Alone with the West End star Michael Ball to raise more money for NHS Charities Together. Ball said he hoped the single, which also features the NHS Voices of Care choir, would reach No 1 in time for Moore’s 100th birthday on 30 April. The track features a spoken word introduction by the veteran saying: “Hold your head up high/ And don’t be afraid of the dark.” Ball said: “There isn’t one of us who has failed to be inspired by Captain Tom Moore. Wouldn’t it be wonderful if we could give him a No 1 record for his 100th birthday?” Moore said: “I never in my wildest dreams imagined I would be releasing a single with Michael Ball OBE, but I also never thought it possible for me to walk in the garden and raise millions. So, why not sing, spread some cheer and again – raise money for our national heroes. NHS, this one is for you!” On Thursday, as he finished his 100th lap, Moore said it was “an absolutely fantastic sum of money”, adding he would be doing less walking on Friday. The Duchess of Cornwall has also written to the veteran. Moore had initially set himself a fundraising target of £1,000 by walking the length of his garden at his Bedfordshire home. Originally from Keighley in West Yorkshire, he trained as a civil engineer before enlisting in the army for the second world war, rising to the rank of captain and serving in India and Burma. The prime minister’s spokesman told a Westminster briefing: “From his military contributions to his support for NHS staff, Tom has demonstrated a lifetime of bravery and compassion. The prime minister will certainly be looking at ways to recognise Tom’s heroic efforts.”