Mark Ronson doesn't want to embarrass "a couple of million people" with his Olympic song.

The producer has joined forces with Katy B to produce a track which will become the theme to the 2012 London Games and admits he is taking his time over it to make sure he gets it exactly right.

He said: "It's taking a s**tload of time. It sounds like a f***ing mess of an idea but it's actually not, it's really amazing.

"You've got to rep your f***ing town. If you make something that's s**t, that's a couple of million people that you're embarrassing."

The 'Bang Bang Bang' hitmaker also explained the track is taking so long because he's gone to great lengths to get the sound of athletes in training for the sing.

He added: "I'm literally strapping all these people who are like Wolverine or the Bionic Man and really getting inside these sounds. That was the theme of the song, to take the sound of athletes and training to make the track and have Katy sing on top of it."

Explaining why he chose dubstep singer Katy for the song, he told NME magazine: "Katy made five of my favourite singles of the last year, so she was my only choice to be on this record and when she said 'yes', I knew that we would make a banger."