Music mogul Simon Cowell has given the stars of One Direction the green light to work on solo projects away from the group.

The What Makes You Beautiful hitmakers are frequently dogged by split rumours as the five members often write their music separately, and Harry Styles has long been tipped as the first to step away to go solo.

Cowell, who helped create the group on Britain's The X Factor in 2010, insists remaining a five-piece is in their best interest but he is happy for them to pursue side projects during their time off.

He tells Britain's Daily Mirror newspaper, "I hear speculation all the time that they're going solo. My advice is they should stay together but still do things they want as a little bit on the side."