It's one of the most highly anticipated sequels in decades after it was revealed that British blockbuster Trainspotting 2 would start shooting in May.

And now Ewan McGregor has been pictured on set in Scotland with his co-stars and director Danny Boyle as he prepares to reprise his role as drug addict, Mark ‘Rent-boy’ Renton.

The Scottish actor was spotted grabbing lunch with the rest of the film’s cast and crew on Wednesday sporting a casual ensemble.

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Guess who's back? Ewan McGregor has been pictured on set for the highly-anticipated film, Trainspotting 2

Blast from the past: Ewan will reprise his role as drug addict, Mark ‘Rent-boy’ Renton

Ewan, 45, did not appear to be in character as he rocked a white top with jeans and a black jacket.

He donned black sunglasses and had his locks in his trademark style while he caught up with Ewen Bremner.

Bremner, 44, appeared to be in dressed in character as Daniel 'Spud' Murphy, teaming a floral patterned shirt with a khaki gilet which featured a sunset image across the shoulders.

His ensemble was completed with grey trousers and while he may be 20 years older than when the 1996 cult flick was realised, he was still recognisable as the lovable rogue of old.

How time flies: Ewan was seen grabbling lunch with cast and crew

Hello there: Director Danny Boyle was seen making his way to greet Ewan during the lunch break on Wednesday

The pair appeared to be delighted to be reunited as they shared a few laughs during their walk.

Ewan looked especially pleased to catch up with Manchester-born director Danny as they nattered away in the midst of the crowd.

Although the plot for the film is based on Irvine Welsh's follow-up novel Porno, it's still unclear what mischief the gang are going to get up to in Trainspotting 2.

For the sequel Ewan has reunited with Robert Carlyle, Jonny Lee Miller and Bremner from the original black comedy - which was nominated for an Academy Award.

New look? Ewan, 45, did not appear to be in character as he rocked a white top with jeans and a black jacket

Or is it? However as the plot for the film is still yet to be confirmed, it may in fact be one of his looks for the sequel

Good to see you: He donned black sunglasses and had his locks in his trademark style while he caught up with Ewen Bremner

They'll each be reprising their roles in the dark film, with Ewan returning as Mark 'Rent Boy' Renton, Jonny as Simon 'Sick Boy' Williamson, Ewen as Daniel 'Spud' Murphy and Robert as Begbie.

Irvine Welsh is also set to appear in the role of Mikey Forrester in the follow-up flick, which is based on his 2002 novel Porno.

Kevin McKidd won't be back as Thomas 'Tommy' MacKenzie since his character died from HIV-related toxoplasmosis.

However, there is still hope for the return of Kelly MacDonald, who was 19 when she was picked from obscurity to play 15-year-old Diane Coulston in the 1996 cult classic.

Robert recently confirmed that filming would be kicking off as joined Trainspotting's literary author Irvine at The Usher Hall in Edinburgh to mark the film's 20th anniversary.

Let's try this: Bremner, 44, appeared to be in dressed in character as Daniel 'Spud' Murphy, teaming a floral patterned shirt with a khaki gilet which featured a sunset image across the shoulders

Hardly changed: His ensemble was completed with grey trousers and while he may be 20 years older than when the 1996 cult flick was realised, he was still recognisable as the lovable rogue of old

Just like old times: The trio appeared to be delighted to be reunited as they shared a few laughs

He explained: 'We start shooting, I understand, in the middle of May and I think it's going to be pretty much 50-50 between Edinburgh and Glasgow.

'I'm basing this on nothing other than the fact that the production office is on Bathgate. There's a clue there.

'What I will say is that all the characters are exactly where you would want them to be.'

He continued: 'The strength of this new script is the fact that the narrative is a bit stronger than it was in the original.

Get in line: The actors were more than happy to wait in the long queue to get their food and drink

Let's do this: Although the plot for the film is based on Irvine Welsh's follow-up novel Porno, it's still unclear what mischief the gang are going to get up to in Trainspotting 2

Dream team: For the sequel Ewan has reunited with Robert Carlyle, Jonny Lee Miller and Bremner from the original black comedy - which was nominated for an Academy Award

'In the first one, when you think about it, it's hard to remember what they did other than get together, the drug deal at the end, and then it's over.

'This has maybe got a wee bit more to it in terms of what they've been up to through these years. You learn a lot about Renton, Sick Boy and indeed Begbie and where their heads are.

'I think it's an absolutely fantastic script. John Hodge has done a wonderful job, as he did with the original.'

And, despite previously admitting to having reservations about the cast reuniting for another film, he added: 'Fingers crossed people will take it on board and they will enjoy it.'

He said in an interview earlier this year: 'It's nerve-wracking to a certain extent, because I'm obviously aware of just how much people loved the original film.

Begbie's back! Robert Carlyle was also seen arriving on set to begin work on the sequel

Back again: They'll each be reprising their roles in the dark film, with Ewan returning as Mark 'Rent Boy' Renton, Jonny as Simon 'Sick Boy' Williamson, Ewen as Daniel 'Spud' Murphy and Robert as Begbie

Time to get involved: The sequel is set ten years after Trainspotting and sees the characters cross paths again, but in the pornography business rather than heroin use as the gritty backdrop

Just one of the gang: The actors were seen taking their hot meal over to another location

'People still quote lines to me on a f***ing daily basis. I get it everywhere; I can't f***ing escape it! But I'm grateful for it too - [my character] Begbie has been f***ing terrific for me and my career.

TRAINSPOTTING 2: WHAT WE KNOW SO FAR Although the plot for the film is based on Irvine Welsh's follow-up novel Porno, it's still unclear what mischief the gang are going to get up to in Trainspotting 2. For the sequel Ewan McGregor has reunited with Robert Carlyle, Jonny Lee Miller and Bremner from the original black comedy - which was nominated for an Academy Award. Original director Danny Boyle will once again take the helm, while the script was adapted from the novel by screenwriter John Hodge. Choose life: Trainspotting amassed an impressive £48m at the worldwide box office The 2002 novel Porno is set in world of adult entertainment and picks up with the characters ten years after the events of Trainspotting. Instead of their heroin addictions being the focal point, this time they cross paths because they all working or connected to the porn industry. Sick Boy – who is using crack - decides to make pornographic films and enlisting the help of his old pal Renton. Trainspotting was shot in Glasgow for seven weeks on a £1.5m budget, but it managed to amass an impressive £48m at the worldwide box office. Advertisement

'So therefore - and I think probably if you asked the rest of the boys, they'd feel the same - I'm slightly wary about it all.'

Robert and Irivne added that Begbie is a uniquely Scottish thug that cannot be found in their adopted homes in America.

Begbie relishes up close and personal violence, in contrast to the USA where violence is 'all about the gun', they explained.

The sequel is set ten years after Trainspotting and sees the characters cross paths again, but in the pornography business rather than heroin use as the gritty backdrop.

Meanwhile, in a recent interview with Collider, Hollywood heavyweight Ewan said of the forthcoming film: 'We haven't started yet, we start shooting at the end of May. The script only arrived very recently, which was really, really, really good.

'I think, if that had not happened, none of us would be into it. I think we're all sort of somewhat protective of what Trainspotting means to people, and what it means to us.'

The actor also insisted he wouldn't have signed up for the sequel if it hadn't had an 'extraordinary script'.

Ewan added: 'None of us want to make a poor sequel to it. So had we not been presented with the most extraordinary script, which we were, I think we wouldn't be making the sequel. But because we were, we are.'

The film is expected to follow a storyline similar to that in Porno, which sees Simon 'Sick Boy' Williamson enlist his pal Mark 'Rent Boy' Renton to help him make a porn film just as Francis 'Franco' Begbie is released from prison.

Trainspotting was shot in Glasgow for seven weeks on a £1.5m budget, but it managed to amass an impressive £48m at the worldwide box office.

The British dramedy - set in Edinburgh - is considered a classic by critics and it also spawned two thrilling soundtracks.

Its famous 'Choose Life' slogan is one of the best known quotes from a modern film, and posters bearing the motto adorn the bedrooms of many a Trainspotting fan across the world.