Londoners were seeing double after an impromptu live busking performance by not one, but two Olly Alexanders.

The British pop sensation shocked his doppelganger by gate-crashing their gig, inspiring a spontaneous 30-minute performance which surprised commuters at St Pancras Station.

The lookalike tribute named ‘Starstruck’, also known as Keith Marshall, normally tours festivals and events throughout the UK.

After kicking off what he believed to be a solo busking performance, he’d made it halfway through the iconic Years & Years hit, Desire, when the real Olly revealed himself on stage to ‘double’ everyone’s fun.

It comes as research of 2,000 adults, commissioned by Twix to launch its new brand platform ‘Two is more than one' revealed two in five Brits are fascinated by doppelgangers, with 78 per cent saying they’d love to meet their own.

Singer and actor, Olly Alexander, said: “It was nice being able to perform with my wonderful doppelganger, Keith.

“Why have one of something when you can have two? I hope the crowd had as much fun as I did.”

The study also found it is Gen Z (66 per cent) who would be keenest to have a doppelganger to step in for them most, followed by Millennials (51 per cent).

The youngest generation would also utilise them to clean up after them, do the washing up – and go to work for them, to sit through boring meetings.

But Boomers would have a double take on their DIY chores they can’t be bothered to do.

Two thirds (67 per cent) would put their duplicate to work tackling household tasks like the washing up and laundry, while 26 per cent would send theirs to social events they don’t want to go to.

And 26 per cent would use their clone to sit through boring work meetings, while 25 would have them wait in for a delivery for them.

Others would use them to get out of having to make small talk with people they don’t want to talk to, read through long contracts or T&Cs or do the food shopping.

If they had a double, 49 per cent think their life would be at least twice as easy.

With 42 per cent thinking it would be more fun if they had someone who looks like them temporarily taking their place.

And 24 per cent would use them as their assistant, rather than their equal.

Holidays (57 per cent), nights out (51 per cent) and road trips (48 per cent) were the activities believed to be better when done in a pair.

Almost half (47 per cent) would get more done if they had a double, while 34 per cent would be much happier and less stressed.

The research, carried out via OnePoll, found 55 per cent believe they don’t have enough time for everything they need or want to do in general.

Blaming this on there not being enough hours in the day (48 per cent), taking on too many responsibilities (34 per cent) and unexpected things always coming up (33 per cent).

It also emerged 37 per cent have already been mistaken for someone else before, with 53 per cent intrigued by the idea that there is someone in this world that looks just like them.

While 49 per cent would love to meet their own doppelganger, if given the chance.

And 38 per cent would be interested in creating their own AI-generated doppelganger in the future.

The latest brand platform ‘Two is more than one,’ nods to its classic two bar serving – because Twix aims to give you a good thing twice.

Lauren Godfrey, senior brand manager from Twix said: "In a world where time is precious, having a clone would be the ultimate life hack.

“While we may not have doubles of ourselves just yet, we’re pleased to have doubled the fun for many of the public today.

“It’s important to make time for little treats amongst the day to day.”