Hyundai and Ford queue up to take on the Prius

As global sales of hybrids continue to rise, there's no doubting that it's the Toyota Prius that is still the car most closely associated with the fuel-and-emissions-saving technology.

Last year Toyota shifted more than 400,000 Priuses around the world, making it by far the bestselling hybrid anywhere.

Other carmakers, trying to compete, have often found the competition particularly arduous. Honda has, for instance, shut down production of its Insight model, and no other carmaker has been able to come up with a vehicle so appealing.

That hasn't stopped both Ford and Hyundai reportedly preparing direct Prius rivals, both of which should be on sale by 2018 – coincidentally, the 21st birthday of the original Prius model.

Ford's entry will, unlike its current (US-only) Fusion and C-Max hybrids, be a stand-alone model, based on the architecture of the next-generation Ford Focus. Apparently set to be produced in Ford's homeland of Michigan, the new model will, like the Prius, also eventually spin off into different body styles.

Hyundai’s plan is similar. Engineering mules for its new hybrid model have already been seen running up mileage, and it will be based on the underpinnings of the next-generation i30 hatchback.

As with the Prius and as with the Ford, more than one body style will be available, with a five-door hatchback and a seven-seat MPV expected to take on the challenge of the Prius and Prius+.

Chevrolet has announced it will produce a second generation of its expensive range-extender Volt, due for launch in 2016.