WALKING down Glasgow's Great Western Road, David Hayman – one of Scotland's most acclaimed actors of stage and screen – suddenly looks up, stops the conversation mid-flow and throws his head back in mock horror. There's his face, looking down at us from the side of a double decker bus. It's an advert for Finding Your Feet, a new romantic comedy starring Imelda Staunton, Timothy Spall, Celia Imrie, Joanna Lumley and Hayman himself, due out next month. A coming of age story with a difference, it explores how Sandra, a woman in her sixties played by Staunton, rediscovers herself on the dance floor after her husband has an affair. For Hayman, best know for his roles as a Glasgow hard man or cynical cop, its a bit of a departure.

"I'm not renowned for romantic comedies," he laughs. "Now I'm 70 years old and I'm on the side of a bus because of one."

He may have just entered his seventh decade – it was his birthday on Friday – but Scotland's iconic character actor, who has played everyone from Scottish gangster-turned-sculptor Jimmy Boyle to Shakespeare's classic King Lear (for which he won lavish praise) is showing no signs of slowing down. With roles in three movies due for release, two documentaries slated and plans to direct another major feature film he may even be busier than ever. All that and he still runs his humanitarian charity Spirit Aid alongside this – oh, and he's just found out he's going to be a granddad for the first time later this year to boot.

First up is Finding Your Feet, which he says with a twinkle, has been "terrific fun" reuniting him with Spall, Imrie and Lumley, all of whom he's worked with before. "One day Joanna and I had a five hour dance rehearsal with just a 10-minute break," he says. "We were hot and sweaty and red in the face. I stopped and said "look at me, I'm 68!" and I hear Joanna shout from across the room "I'm f*****g 70, darling". What can you say to that?"

Hayman says there is a positive message in the rom-com. "What this film is saying is if you're in your sixties, life is far from over, get off you arse, get out of your comfort zone and find your feet. Go and try something. Be brave." It's a message he could be said to have taken to heart.

If Finding Your Feet shows you can still have fun and fall in love as a pensioner, Hayman's other big project, The Hatton Garden Job, shows that pensioners can also be bad to the bone. In the new TV series he plays one of the old lags who robbed the underground safety deposit facility at London's Hatton Garden in April 2015. They used high-duty drills to get into the vault, going through wall that were two metres thick and cracked into 73 boxes in the vault.

Each box contained a wealth of jewels and precious metals including diamonds, sapphires and gold. Eventually the men, who were all experienced thieves, were caught and pleaded guilty. He plays Danny Jones. "I put a request in to ITV, can I go into prison and meet him [Danny Jones] and they said no," he sighs. "It was fascinating. The audacity of these men in their sixties carrying out an old school robbery."

This year will also see him star in Dirt Road To Lafayette, a low budget movie and Scottish author James Kelman's first screen play which tells the story of 15-year-old Murdo's journey from Scotland to North Alabama to visit relatives after his mother's death. Then there's Fisherman's Friends about a Cornish folk group made up of fishermen who got a record contract in 2010 and made it to the top 20. "They even played the Pyramid stage at Glastonbury," adds Hayman. There's "morality thriller" The Corrupted and Men of Steel, a new film he is currently casting – and hoping to direct in a year or so – about the upper Clyde shipyard workers, in the era of trade union leader Jimmy Reid, which he says has never been more timely. On top of that mammoth workload, there are two TV documentaries out this year, which take in issues "close to his heart" including land reform and Scotland's role in slavery. "I always assume I will be busy," he say.

He still insists it was acting that called to him rather than the other way round. He spent the first six years of his life in a single end and kitchen in Bridgeton in Glasgow's east end before the family were relocated to Drumchapel, a new scheme on the edge of the city. It was here, during a "very happy childhood" that he discovered a love of the countryside that lay just beyond the hill on which his primary school was finally built – for years he was bussed into Anderson to attend school. Then at age 16, he followed his father into the shipyards as an electrician.

"One day I was coming back from work in my boiler suit and I got off the bus, walked up the steps of the Royal Academy of Music and Drama and I burst through the registrar's doors. Then a voice said: "I want to be an actor". It was mine. I don't really know where it came from. I was crippled with shyness as a kid. I must have been called to it in some way – I know that sounds a bit w**ky but..." He shrugs. "It was almost as if I was on automatic pilot."

His father – perhaps believing it was a rejection of the macho role model he'd provided – was not initially impressed. In fact it wasn't until his workmates noticed "his boy on the telly" as Jimmy Boyle in the critically acclaimed 1979 movie adaption of A Sense Of Freedom that he came round to the idea.

"Then I was pigeon-holed," he says. For years the film roles he were offered were for hard men from DCI Walker in Lynda La Plante's Trial and Retribution TV crime series to McGowan in Ken Loach's gritty feature about a debt collector, My Name Is Joe.

"It's probably taken me all this time to break out out of the typecast role," he says. But he does love a baddie. "To play evil, power, ruthlessness – there's a journey to go on there," he says. "It's lovely to think 'can I find a chink in that armour of evil' – is there someone who has been bruised or abused or damaged that explains their behaviour there? That is what I find fascinating."

Yet his favourite character to play has still been Bob Cunningham, a character created by his friend, the Scottish playwright Chris Dolan, for two one-man shows staring Hayman – and made in response to the pair's growing support for the Scottish Independence in 2014 – called The Pitiless Storm and The Cause of Thunder. "I said, 'Chris, why don't we create something that's about our journey as working class men, stamped as Labour at birth, to now voting for an independent Scotland run by the SNP?'." The result was, for Hayman, "art and life and politics all coming together in one show".

"That's rare. That was the most exhilarating thing. When another referendum is called we're going to write a third play and we'll take it on the road again." Unsurprisingly, then, it looks like the irrepressible David Hayman plans to be busy for a good few years yet.

HAYMAN: REFORM CREATIVE SCOTLAND

THE controversy over funding decisions made by Creative Scotland last month, which led to widespread protest from high-profile artists and the resignation of two of its own board members should lead to a revamp of the national cultural public body, according to David Hayman.

David Hayman claims the controversy over decisions to cut "regular" funding [core funds provided over three years ] from theatre companies, galleries and other arts organisations, five of which were last week reversed, showed a need to look again not only at how decision were made but at the function of Creative Scotland itself.

He insisted it was now time to reverse the unpopular decision to merge the Scottish Arts Council and Scottish Screen in 2010 and return to having two separate bodies, one for the film industry and one supporting non-sustaining art forms.

"I think that they really need to look at themselves now and revamp it [Creative Scotland]," he said. "For years now I've felt to merge the Scottish Arts Council and Scottish Screen was madness. Filmmaking is an industry, theatre is an art form. They should have separate organisations funding them. But they really need to talk to the creative community and say 'how can we better help you, how can we better work in partnership with you rather than dictating on high'. There really needs to be a revamp."

He also criticised the lack of progress on the creation of a national film studio, support for which has been called for by the film industry for decades. Planning permission on a proposal for the country's first purpose-built film and TV studio in Midlothian was finally granted in December last year.

"It takes the Americans to come in and build a shed where they shoot Outlander and that's the nearest thing we have to a film studio," said Hayman. "Think of all the movies that we've lost, all the money that we've lost all the way back to Braveheart."

Ben Thomson, interim chair of Creative Scotland said: "Funding decisions of the scale and importance of regular funding are always extremely challenging. We have listened to the extensive and constructive feedback we received from many individuals and organisations working across the arts and culture in Scotland." The organisation stressed it has reallocated £2.6 million to ensure five theatre companies facing cuts were funded. A spokeswoman acknowledged the importance of a national film studio and welcomed planning permission approved in principle.