The Christmas number one spot is the most sought after chart position for all musical acts given the increased revenue that can be expected from the increased festive sales.
If a single tops the chart the week in which Christmas Day falls then it is deemed as the Christmas number one.
In the past 10 years this has mainly been dominated by the winner of The X Factor, since the winner is normally announced just a week or so before Christmas and fans are eager to purchase a copy. However as viewing figures decline for Cowell's baby there is an opening for an alternative record to take prime position.
Remember 2009 when an online campaign saw Rage Against the Machine's Killing in the Name resurrected to take the top spot as a protest to the norm?
Christmas Number One 2016 – Clean Bandit, Rockabye
Preivous Christmas number ones
2016 - Clean Bandit 'Rockabye'
2015 - Lewisham & Greenwich NHS Choir 'A Bridge over You'
2014 - Ben Haenow 'Something I Need'
2013 - Sam Bailey 'Skyscraper'
2012 - The Justice Collective 'He Ain't Heavy, He's My Brother'
2011 - Military Wives with Gareth Malone 'Wherever You Are'
2010 - Matt Cardle 'When We Collide'
2009 - Rage Against The Machine 'Killing In The Name'
2008 - Alexandra Burke 'Hallelujah'
2007 - Leon Jackson 'When You Believe'
2006 - Leona Lewis 'A Moment Like This'
2005 - Shayne Ward 'That's My Goal'
2004 - Band Aid 20 'Do They Know It's Christmas?'
2003 - Michael Andrews & Gary Jules 'Mad World'
2000 - Bob The Builder 'Can We Fix It'
2001 - Robbie Williams & Nicole Kidman 'Something Stupid'