A composer has turned the tune that David Cameron casually hummed as he walked into No 10 after announcing his resignation date into an "evil anthem" fit for Darth Vader which has gone viral on Facebook.

Chris Hollis, from Hitchin, Hertfordshire, was inspired after he saw the footage on Monday during which an ITV microphone picked up the Prime Minister humming the tune.

After Mr Cameron walked into his official residence and office, he was heard saying "right" before the door closes behind him.

Posts on social media have made comparisons with Winnie-the-Pooh and Homer Simpson, while others have suggested it is the end of the theme song from hit US TV drama The West Wing, which follows the career of a fictional Democratic president and his advisers in the White House.

But Mr Hollis has taken the tune to another level and transformed it into a composition similar to the Imperial March from the 1970s hit sci-fi movie Star Wars.

The Facebook video of Mr Hollis's work, entitled Cameron unveils brand new evil Tory theme tune, has so far been viewed more than 200,000 times.

The 34-year-old told the Press Association: "I'm a full-time composer and I'd just finished a session when I saw the clip of Cameron singing his little ditty on the news, and thought 'it's only a matter of time until someone writes music to that' and then, as I had a spare 15 minutes, thought it may as well be me.

"I think the mood in the UK seems very low right now so it was nice to see my little tune raise a smile or two."

The posting has received hundreds of comments, including from Catriona Cochrane who posted: "Just wunnerful ... ( weeps in despair at the state of the state ....)"

Melanie Quinn said: "I gave birth I laughed so hard."