The 100-year-old war veteran spoke to Metro.co.uk’s weekly mental health podcast, Mentally Yours, on the importance of looking after the elderly over Christmas.

He said many people ‘were not feeling very happy’ at the moment but that small acts of kindness, such as sending a relative or neighbour a Christmas card, could go a long way.

He said this was particularly true for people at risk of being isolated over the festive season due to coronavirus restrictions.

‘Send someone a little Christmas card or a little message over Christmas, you could call them on the phone, a face call I am sure would be the happiest thing,’ he said.

‘You can go all over the world [with FaceTime], it’s not just the next street, if you can speak to someone miles away and let them see your smiling face… I am sure they will be delighted, I certainly would be.’

The national hero, who shot to worldwide fame after raising £32 million for the NHS during the first lockdown, pleaded for those who can to ‘knock on the door’ of neighbours and relatives to check they are not being neglected.

‘Try and make contact with them,’ he said.

‘Those that need help but don’t know it, they are in a position where it is up to us to put them into contact with someone who is mentally capable of helping them.’

He added that young people struggling to cope during the second lockdown could learn a lot from older people by listening to their stories on living through the war and other hard times.

In a plea to the younger generation he said: ‘Find out as much information as you can from your parents and your grandparents and store that knowledge for the future because when the old people have gone, that information is also gone.’

Sir Tom shot to worldwide fame after raising £32 million for the NHS

Sir Tom was hailed a ‘beacon of hope’ after completing 100 laps of his Bedforshire garden before he turned 100 during the first wave of the pandemic.

His positive and fighting spirit won him praise from politicians, celebrities, sports stars and even the Royal Family, with the Queen knighting him earlier this year.

On getting through the winter lockdown he advised people to take each day as it comes.

He said: ‘So many people are not feeling very happy at the moment, I think it is up to us wherever we can to give a little bit of kindness to everyone, even if it’s hard.

‘At the moment we have got a lockdown and there’s so many days ahead. If people just think yesterday is one day of the lockdown that’s gone, today is going to be another one and tomorrow is going to be another day.

‘Gradually we are getting through the lockdown…gradually it is getting less and less, day by day, and what was today is now yesterday.

‘Lets look forward to the future and if ever you see people walking about, give them a little smile and see if they will smile back, because a little smile won’t do any harm to you or to them.’

Last week the war veteran launched a campaign urging the country to walk and talk together during the second lockdown. His charity The Captain Tom Foundation wants people to share their journeys, whether it be 100 laps, a marathon or a toddler’s first steps, using the hashtag #WalkandTalk

Appearing on Mentally Yours alongside him, Sir Tom’s daughter Hannah Ingrahm-Moore said people turned to the family ‘for words of wisdom’ after the new restrictions were announced, so the idea for Walk and Talk with Captain Tom was created.

Hannah said that combating loneliness is ‘so meaningful’ to Sir Tom and ‘so poignant to us as a family’ due to seeing his late wife Pamela in a care home, when they realised some people never had visits.

Giving her own advice for getting through a winter of coronavirus restrictions, she said that ‘the young can learn from the old’ by asking them stories about growing up in post-war Britain, while the old can also learn from the young.

‘The young people who have never been through anything like this before can learn from the ones who have and the old who feel isolated can learn from the young through technology,’ she said.

She added that Sir Tom had ‘been round the world’ with her mobile phone, revealing he had done hundreds of interviews in the 163 countries that donated to his fundraiser.

‘If you have a will to do it, you can,’ she said.

She added: ‘Write, pick up the phone, use technology, we have to get through this and we have to find the best way that we possibly can. We can still put pen to paper, we can still walk to the post box, there’s nothing really quite like receiving a letter or a handwritten card is there.

‘Any form of contact, lets embrace the technology that wouldn’t have been here even a few years ago.’