The girl group's latest track 'What About Us' featuring Sean Paul is currently outselling its nearest rival by two copies to one.
Justin Timberlake slips to number two with 'Mirrors', while Pink stays firm at three with 'Just Give Me A Reason'.
Bruno Mars is at four with 'When I Was Your Man', Bastille are at five with 'Pompeii' and Kodaline start at 13 with their new single 'High Hopes'.
Further down the chart, 30 Seconds To Mars land at 35 with their new song 'Up In The Air' after 24 hours of release, while Paramore are at 37 with their new cut 'Still Into You'.
Timberlake looks set to claim the number one spot on the album chart with his comeback album The 20/20 Experience.
The collection has sold 57,000 copies so far, pushing David Bowie's The Next Day down to two.
Les Misérables is at three, Emeli Sandé's Our Version Of Events is at four and Bastille's Bad Blood is at five.
Suede land at seven with their new collection Bloodsports, Daughter are at 13 with their debut album If You Leave and Hadouken! are at 16 with Every Weekend.
> The Saturdays: 'We'll always be hoping for a No.1 single'
Watch the music video for The Saturdays' new single 'What About Us' below: