South Yorkshire firefighters have performed a sell out gig to kick start their assault on the Christmas number one spot, in what bookmakers say could be one of the greatest shocks in chart history.

Thousands of people saw Central red watch firefighters perform ‘Chip Pan’ on stage with the Everly Pregnant Brothers at Sheffield’s O2 Academy.

The song tells the cautionary tale of a man who sets his house alight after a night out drinking and goes on sale on Friday.

A video which accompanies the track clocked up more than half a million views online within days, prompting bookies to halve their odds on the song reaching number one.

The track is being released to remind people of the contribution of firefighters who will be on duty this Christmas Day. The campaign has won the backing of fire and rescue services from every corner of the UK- and even as far afield as Canada, Australia and the US.

Assistant Chief Fire Officer Martin Blunden, said: “We’re going for Christmas number one to remind people that tens of thousands of firefighters and other emergency services staff across the country will be working this Christmas Day to keep you safe, including red watch firefighters and control staff who helped to make the video which accompanies the song.”

William Hill spokesman Rupert Adams said: “Every now and then you come across a song that should have no chance but this is great fun and ticks many boxes. We have already slashed the odds and this could be one of the greatest shocks in chart history.”

Good causes will benefit from the assault on the festive song summit, with cash raised from sales of the single going to charities Age UK and Shelter.

‘Chip Pan’ by the Everly Pregnant Brothers is available to pre-order on iTunes, Google Play Music, Amazon, Spotify and Deezer. But to give the song the best chance of reaching number one when the official Christmas chart is released, the public are asked to only download the song after 16 December.