All-new hatchback ousted in leaked images, showing off its refreshed design. Expect an official debut at the Frankfurt motor show in September.

The new-generation BMW 1 Series has been leaked online, ahead of an anticipated reveal later this year.

Posted by BimmerFile, the pair of images show the front and rear of the all-new hatchback, in flagship M135i xDrive form.

In terms of the overall design there aren't too many surprises, with the exterior blending elements from across BMW's newest line-up.

Up front there's a strong resemblance to the X1 and X2 crossovers the 1 Series will share its UKL front-drive architecture with, while the angular rear with slim LED tail-lights shows strong family links to the new 3 Series and 8 Series, albeit with the hatchback rump.

Expect the core range to look a lot more sedate than the M Performance variant you see here, complete with an aggressive bodykit and dual exhaust outlets.