The Military Wives on course to be Christmas number one
The Military Wives are on course to be this year's Christmas number one and become the fastest-selling single for six years.
The Official Charts Company said the track, Wherever You Are, sold 242,000 copies in its first two days on sale.
It has shifted more than six times the amount of Little Mix's Cannonball, which is in second place.
The song is the fastest-selling single since The X Factor winner Shayne Ward's 2005 track That's My Goal.
Other tracks set to enter the top 10 include YouTube entrepreneur Alex Day's Forever Yours and Nirvana's Smells Like Teen Spirit.
The 100 wives and girlfriends of servicemen in Afghanistan were brought together for the TV series under choirmaster Gareth Malone.
The series concluded with the choir performing at the Festival of Remembrance at the Royal Albert Hall.
Wherever You Are, put together by Royal Wedding composer Paul Mealor, is inspired by letters to and from their soldier husbands.
The choir's lead singer Samantha Stevenson described it as "a proper song for Christmas."
Last week choirmaster Gareth Malone told Newsbeat: "I thought it might capture the public's imagination because of the woman.
"We've caught a wave of people wanting something real at Christmas.
"We've all been plucked from obscurity and thrust into the glare of the spotlight by this. It's an honour."
This year's festive chart topper will be announced live on Christmas Day on BBC Radio 1.