Mercedes is planning to give its upcoming CLA small saloon an AMG performance range-topper, as this first spy picture of it testing reveals.

The CLS-inspired CLA is due on sale next year in standard guise. It is based on the new A-class and was previewed by the CSC concept at the 2012 Beijing show.

The CLA45 AMG version will follow the standard car into showrooms several months later and will share its all-wheel drive drivetrain with the A45 AMG. That means a 2.0 turbo petrol engine with about 330bhp and 330lb ft. Expect 0-62mph in about 5.0sec.