Music lovers will find out today whether Justin Bieber's support for the NHS Choir can secure them the Christmas number one spot.
NHS Choir began trending on Twitter on Wednesday afternoon after the Canadian pop star called on his fans to "do the right thing" and help charity single A Bridge Over You win, saying that "for one week it's OK not to be number one".
Bieber tweeted: "I'm hearing this UK Christmas race is close ... but the NHS Choir single is for charity. So ...
"So for one week it's OK not to be number one. Let's do the right thing and help them win. It's Christmas. NHS Choir good luck."
He added: "This is what it's all about. Merry Christmas."
In response, bookmaker Coral suspended betting with spokesman John Hill saying: "It's hard to see the NHS Choir not getting the top spot now that Justin Bieber, their only rival, is behind their charity song. Before we pulled the plug we saw a huge gamble on the NHS Choir so it is likely to be a popular result with punters."
Proceeds from the NHS Choir's single will go to charities including Carers UK and Mind.
This is the closest battle for Christmas number one since 2009, when Rage Against The Machine's single Killing In The Name took on The X Factor winner Joe McElderry's The Climb and won.
Martin Talbot, chief executive of the Official Charts Company, said: "As well as climaxing on Christmas Day for just the fourth time in history, this year's race for the festive number one is looking like one of the closest ever."