Ross Kemp's latest documentary series focuses on the uplifting efforts of those making a difference by helping the vulnerable and NHS during this crisis - and there's plenty to be thankful for, he tells Gemma Dunn.

There's no stopping Ross Kemp.

While most of the country has been holed up at home, the former soap star turned investigative journalist has been duly documenting the ongoing Covid-19 pandemic, first with his divisive film Ross Kemp: On The NHS Frontline, and now via a new five-part series, Ross Kemp: Britain's Volunteer Army.

Spread across a week, the latter - set for BBC One - will celebrate the heroic everyday efforts of the nation's hundreds of thousands of volunteers.

It's a coming together of the British public, Kemp offers.

"I've been fortunate enough to have seen NHS frontline workers working in the ICUs, the isolation wings, and that will stay with me for a very long time," the 55-year-old whispers.

"But for me, the biggest thing that comes from what I've seen, in terms of the British public's response to this pandemic, has been the fact that we aren't a very big country, but we do have an awfully big heart.

"When our backs are against the wall, we certainly come together in the most amazing way," muses the Essex-born personality.

He recalls an emotional shoot on a street in High Wycombe recently, whereby he witnessed the heartfelt coming together of the local community.

"I said on my last piece to camera, 'If 20% of what's happening on this street is mirrored elsewhere in the cul-de-sacs and the roads of the UK, and we can keep that after the pandemic has gone, then something very positive would have come from this awfully dark time'.

"It's brought people from different ethnicities, different backgrounds, class divide, religions, different beliefs, together," he adds, at a time when we - as a nation - have never felt so divided.

But while the series reflects the volunteering efforts happening throughout the UK, Kemp himself has remained close to home (within a 30-mile radius, he points out), as part of government guidelines.

Those he encountered on his home turf include a gin distillery making hand sanitiser for local organisations in need of PPE; a rugby club that puts up its match day gazebos to enable medics to safely meet patients; and a woman who organises food donations from local supermarkets and distributes them to underprivileged families with children who rely on a hot meal at school daily.

Meanwhile, those further afield have been self-filming for the series, with Kemp 'meeting' others on Skype or Face Time to find out more about why they feel compelled to help others in their hour of need.

Stories include an ex-military man in Glasgow, who is donating his time and vehicles to help veterans who need food supplies; and two young sisters in Birmingham who are hand-writing letters to elderly care home residents.

"One day I walked into the church where they were collecting donations of food for people - this is in a relatively affluent area, but people are just running out of food - and I just welled up," Kemp remembers.

"I was just absolutely knocked back by the generosity of the human spirit. If we can hold on to some of that, that can't be a bad thing."

Has this process affected him in terms of optimism for our future?

"Have you seen the work I do!?" he quips, laughing wildly at the lack of jollity in his body of documentary work that's seen him explore everything from gang culture to the war in Afghanistan, violence and poverty in his Extreme World series, and most recently HMP Belmarsh.

"I was more of a pessimist when I was 20, and more of an optimist at 50," he offers.

"I'm in the fortunate position to have travelled to a lot of the world and I'm often amazed that you can go to a favela in Rio or a village in the Congo, and people have nothing, yet they can be happier than some of the richest and most affluent people I've met.

"I think what this pandemic has done is made us all a bit more realistic about our outlook; it's been sort of like a reset button, hasn't it?" he asks.

"Being that close to it, when I was in the hospital, and also seeing the generosity and spirit that I saw from the volunteers, it's made me understand - well, I'm pretty familiar with it - just how vulnerable we are in terms of our lives and what's most important to us.

"Is it having a flash car or three holidays a year? Or is it just having the love of your close ones? I would rather spend the summer in the garden with my family and know that we're all healthy, than flog my guts just so I can have an extra holiday or a bigger car."

That's why it's important we remember who the real heroes are here, he notes.

"A 'hero', for me, is somebody who risks their own safety or risks something of themselves to help someone else, and that's true of both what I saw on the NHS front line and also from the volunteers.

"The word 'hero' is bandied about far too often, possibly, but at times like this when there's clearly one enemy, this virus, then I'm more than happy to use it."

As for covering this unprecedented period, its been a privilege, he adds: "It's my first time back at the BBC for 20 years and it's an honour to even be asked to be involved in it, just me and Mark, the cameraman-director."

But he certainly knows his stuff, having made just shy of 100 documentaries in the past two decades - and with plenty more in the pipeline.

In fact, while we've been speaking, Kemp is in transit to film another of his famously hard-hitting factuals, this time focusing on opioid addiction.

Pandemic or not, his work continues, he says candidly: "You're documenting this time, so whether it's a story on opioids or on Alzheimer's, it's [those issues] in the time of Covid-19.

"If you're a drug addict, you're a drug addict," he reasons. "Whether you've got Covid-19 in the background or in the foreground - or not."

As for acting: "I always say, do you know what, when you've got four kids and a wife, you never say no to nothing!" teases the former EastEnders hardman, who's also currently busy with his new podcast, Kempcast.

"But [before I go], one thing I have to say is Britain's Volunteer Army has heart," he finishes.

"Genuine heart of people of all ages, all descriptions, all backgrounds coming together for other people - and you can't put a price on that."

Ross Kemp: Britain's Volunteer Army begins, BBC One, Monday, 10am.