Justin Bieber
Justin Bieber is currently dominating the number one and two positions on the UK chart with his singles Love Yourself and SorryKevin Winter/Getty Images

There could be an unlikely winner in the race for Christmas number one as pop star Justin Bieber is up against the NHS Choir to take the top spot. X Factor winner Louisa Johnson was previously a frontrunner but her unexpectedly poor record sales has opened up the race to a whole new set of contenders.

The Christmas number one will be announced on Christmas Day (Friday 25 December 2015) on BBC Radio 1 in a countdown show hosted by Greg James and during a special episode of Top Of The Pops. With anticipation mounting and the odds constantly changing, the IBTimes UK takes a look at each of the acts currently in the running to top the charts...

Justin Bieber

Pop's reformed character has doubled his chances of scoring the Christmas number one as he is currently dominating both the number one and two slots on the UK chart with Love Yourself and Sorry respectively. However, it is the former single, which features on Bieber's latest album Purpose, that is closing in on the NHS Choir.

NHS Choir

Their lead of 5,000 sales over Bieber's Love Yourself has dropped to 2,000 according to the Official Charts Company but Gareth Malone's choir are still charging ahead of the race. Their single, A Bridge Over You, which is a mash-up of Coldplay's Fix You and Simon & Garfunkel's A Bridge Over Troubled Water, will donate its proceeds to charities Mind and Carers UK.

Adele

Hello was released in October 2015 but the song has climbed back up the charts to number three, placing it as the nearest contender to overtake Bieber and the NHS Choir.

Stormzy

Perhaps the most unlikely contender for the Christmas number one, the grime MC launched his campaign fairly late in the race with his single Shut Up. Incredibly, the track has entered the UK chart at number eight, which is one place higher than X Factor winner Louisa Johnson.

Louisa Johnson

The 17-year-old had been hoping to continue the X Factor winners' tradition by claiming the Christmas number one with her winner's single Forever Young, but the song performed poorly in its first week of release, debuting at a lowly number nine. Although the bookies' previous favourite to soar to number one, Johnson's chances of claiming the top spot are looking very slim.