X Factor 2012 winner James Arthur has passed the 1m sales mark with his debut single Impossible, which was released just moments after he won the series on December 9.

The song – which is the fastest selling single since Alexandra Burke’s 2008 debut Hallelujah, took just four weeks to reach the magic number, passing the 1m mark at midnight on Thursday.

Since its release four weeks ago it has spent three non-consecutive weeks at number one, giving way to the Justice Collective in the Christmas chart but returning to the top spot the following week.

“Hitting the million mark in around a month is a fantastic achievement for James Arthur,” said the Official Charts Company’s Martin Talbot.

“X Factor winners often score strong first week sales but to push through to the million mark so quickly is truly impressive.”

Impossible is now the fourth biggest X Factor debut single behind the efforts from Burke, Shayne Ward and Matt Cardle.

However its chances of spending a fourth week at number one on Sunday are currently being threatened by the Britney Spears-will.i.am duet Scream and Shout.