A 99-year-old veteran who is walking 100 lengths of his garden to raise cash for the NHS has been hailed as an “inspiration”, with donations set to surge past £12 million.

Captain Tom Moore, who lives with his family in Bedfordshire, is due to complete the last of the 25-metre laps on Thursday.

His achievements – which started at a modest target of £1,000 last week, ahead of his 100th birthday on April 30 – were singled out by Matt Hancock during the Wednesday evening press conference at Downing Street.

In his opening address, the Health Secretary said: “I want to pay a special tribute today to Captain Tom Moore.

“Captain Tom, you’re an inspiration to us all, and we thank you.”

At that point, donations had surpassed £8 million.

When the figure hit £10 million late on Wednesday night, an overwhelmed Captain Moore tweeted “Virtutis Fortuna Comes” – the Latin motto of the Duke of Wellington which means “fortune is the companion of virtue”.

By the early hours of Thursday, the figure had hit £11.8 million.

Earlier, Captain Moore told BBC One: “I think that’s absolutely enormous.

“At no time when we started off with this exercise did we anticipate we’d get anything near that sort of money.

“It just shows that people have such high regard for matters of our National Health Service and it’s really amazing that people have paid so much money.”

Mr Moore began raising funds to thank NHS staff who treated him for a broken hip.

His daughter, Hannah Ingram-Moore, told the BBC that the amount raised was “beyond our wildest expectations”.

He’s a stoic Yorkshireman, he’s an unruffled straight-down-the-line kind of person and has embraced this adventure as the next stage of his life

When the JustGiving page went live last week, they thought their £1,000 target was a “real stretch”, she said.

“No words can express our gratitude to the British public for getting behind Tom, for making this into a heartfelt story,” she added.

“He’s a stoic Yorkshireman, he’s an unruffled straight-down-the-line kind of person and has embraced this adventure as the next stage of his life.

“I believe that life is all about purpose, we all need purpose, and, whilst he’s had a life full of purpose, he did fall and break his hip and became much less independent than he had been for the preceding 98 years, and what you have done, the British public, and everyone who’s supported him, is giving him his next purpose.

“He is articulate, he’s alive, he’s doing this and I think he’ll do this until everyone says, ‘Stop, don’t do it any more’.”

Originally from Keighley in West Yorkshire, Mr Moore trained as a civil engineer before enlisting in the Army for the Second World War, rising to captain and serving in India and Burma.

Meanwhile, an eight-year-old girl has started an online campaign for children to make birthday cards for Mr Moore’s 100th birthday.

Reegan Davies, from Port Talbot, South Wales, set a target of 1,500 virtual cards after posting a video online to thank him for his fundraising efforts.

She says in the video posted on Twitter: “You’ve got to make a birthday card for Tom, any social media you post it, and tag #makeacardfortom”.

– Donations to NHS Charities Together can be made at www.justgiving.com/fundraising/tomswalkforthenhs