The electronic duo explained that they were invited by the BBC to submit a song for the annual contest, but that the track 'Winner' eventually morphed into their own anthem for the London 2012 Olympics.
"It was slightly with Eurovision in mind," Neil Tennant told BBC Breakfast. "The BBC asked us if we were interested, then when the album came out it seemed like the right time to release it."
The pair performed their classic hit 'West End Girls' at the Olympics closing ceremony last month, while they also performed their new song at the victory parade in London last week.
"[The closing ceremony] was really exciting, the atmosphere was amazing," Tennant said.
He added: "Without sounding patriotic, you do feel quite honoured when you're asked to represent [your country]."
Pet Shop Boys recently spoke to Digital Spy about the Olympics, and also praised leading boyband One Direction.
Their latest album Elysium entered the UK album chart at number nine yesterday (September 16).
Watch the video for 'Winner' below: