David Cameron's ukulele busker: 'I thought 'f*** off back to Eton' was a bit crass, but it came from the heart'

Gillian Duffy, Joe the plumber; in an age when elections focus increasingly on the personalities of leaders, every now and again a member of the public briefly seizes the limelight to revel in their 15 minutes.

Cometh General Election 2015, cometh Robin Grey: as David Cameron waltzed his way through the streets of Alnwick, Northumberland, he was rudely interrupted by a ukulele-playing man who told the Prime Minister to "f*** off back to Eton". Cameron ignored Grey, although one his minders told him to tone down his language.

The Independent met Grey as he returned to London, where he lives in Hackney, having visited his grandmother in Northumberland, hence his unexpected rendezvous with Cameron. Grey said that as he approached Alnwick on his bike, he had to brake suddenly as a car stopped in front of him to halt traffic and allow the Prime Minister's battle bus to emerge from a side road and into the town.

Grey said he was upset at seeing the Prime Minister in Alnwick: he didn't like the way Cameron's walkabout town was so stage managed. He alleged: "There were people just passing by who wanted a selfie with the Prime Minister, but the ones he stopped and talked to were selected. They'd very carefully picked people around different parts of Alnwick." Grey felt an urge to sing a protest tune.

Grey, 36, a folk singer and community activist, spends a lot of time working in primary schools teaching the ukulele, where coming up with a quick ditty is commonplace. "I didn't know what to sing and the minute I started singing it ('f*** off back to Eton') I was like, that's a bit crass, I thought I could do better than that. But I just kept on going, because it was coming from the heart."

Grey went to "a massive mixture of schools", including fee-paying institutions on bursaries and scholarships, but for him his outburst is not about class conflict in a traditional sense. "It feels to me that the image of the rich versus poor needs to be transcended by the rich and the poor versus the super rich, because that gap is opening up so widely," he said.

"At the time, the song just came from the gut, but thinking about it in hindsight, I think Eton symbolises a lot of what is wrong with this country. We have a tiny clique of very over privileged men, with an over-inflated sense of entitlement and they still hold the status quo in terms of power, land and money."

Such a view resonated with some, although they were aware that attacking Cameron's upbringing was divisive. Andrew Smith, 46, arrived in Kings Cross to play with Grey after he had spread word on social media about a "ukulele flash mob". He said his kids had been singing Grey's tune at school, although that was probably because of the rude word rather than the message.

"I don't mind the fact that he's been educated at Eton, everyone's got to go to school somewhere," Smith said."I do mind the fact that a small, very rich elite are strengthening their grasp on so many aspects of society."

Catherine Rogan, 34, had also seen Grey's Cameron serenade, thought it "was great", and gone down to Kings Cross for a duet.

"I've had a few people saying why does it matter that he went to Eton?" Rogan said. "Well, he had a very, very privileged upbringing and the Government is just a big school reunion for him...It's a bit of light-hearted humour. Nobody is seriously going to evict him and make him go back to Eton for the rest of his life."

For Rogan, such an injection of humour is needed during this election: "It's all got a bit domestic, and kitchens, and wives, and pork pies and personalities."

Would Grey consider writing more political tunes during this election cycle? "I would really like to write a song about how inspiring I found it having three women in the leaders' debate," he admitted. "I think the significance of that is just something that really needs to be celebrated.

"I would really love to craft that and put a lot more care into that. I don't think I’m going to be in the situation where the three leaders of those parties walk in on me and I have to improvise that in a few seconds."

For now though, Grey's Cameron tune has attracted the attention of Peter Wells-Thorpe, the president of the 3003 Group, an international media and marketing group. He heard Grey's song, "burst out laughing", and approached him to record the tune to be released as a single.

"It’s in the great British music hall tradition: catchy song, no nonsense lyrics, pricking the pompous," Wells-Thorpe said, who thinks the song will work well as a single: "It's got a great hook and it's easy to sing along with".

Yet for some, Grey's tune can still be interpreted as a class-bashing, foul-mouthed tune, and therefore not the best way to get a political message across. It may even embolden those on the Prime Minister's side.

"I absolutely thought so, yes," Grey replied. "But the reaction I've had from the British public has convinced me otherwise.

"It's lyrically crass, but people have connected with it. It wouldn't have been my first choice., but what’s happened, has happened. It would be lovely if I wasn't the person who sung to David Cameron on a ukulele, but there's worse things I could be known for."