7 Weeks: Mark Ronson & Bruno Mars - 'Uptown Funk'
This image appears in the gallery:
The Longest Reigning No.1 Singles In Big Top 40 History

2. 7 Weeks: Mark Ronson & Bruno Mars - 'Uptown Funk'
The single spanned over both 2014 AND 2015 after it was rush released after Fleur East performed the tune on the X Factor.