A high-performance Ford Focus RS500 is awaiting the final production go-ahead for a launch next spring.

The Ford Focus RS500 could be canned

The limited-run RS500 is under development in Germany by Ford Performance as one of 12 high-performance models due before 2020.

The go-ahead is understood to hinge on practicalities such as whether the 500 limited-run models can be added to the Focus production line in Cologne without too much disruption and ensuring there’s a business case for the RS500 to be a financial success.

Ford won’t discuss future products, but a source told Autocar that the RS500 is “not genuinely green-lighted, but the desire exists to have a star in the RS and ST range”.

An important part of the plan, as well as providing enthusiasts with one of the quickest and best-driving hot hatchbacks yet, is to keep up interest in the cooking models of the third-generation Focus as it enters the run-out phase in the summer of 2017.

Technical details of the RS500 are thin on the ground, but a prototype spotted at the Nürburgring suggests bonnet cooling vents and a larger rear spoiler are under development.

The bonnet cooling vents are a clue that Ford is planning a power boost for the new RS500. Vents were a distinguishing feature of the first Focus RS500, which went on sale in spring 2010 to boost run-out interest in the second-generation Focus.

That original Focus RS500 had its 2.5-litre five-cylinder engine’s power lifted by 15% to a then-spectacular 345bhp. However, such is the pace of development of mega-hatches that 345bhp is now the output of the standard Focus RS.

If Ford adopts a similar tuning approach for the new RS500, it could be looking at a mighty 396bhp from the same 15% power hike. That would be a highly tuned 172bhp per litre, but that’s comparable with the 177bhp per litre of its Mercedes-AMG A45 rival.

Torque increases are likely to be more modest, if only to ensure that Ford doesn’t need to re-engineer the RS’s six-speed manual gearbox and four-wheel drive system, which is built around a clever GKN active rear differential.

That rear diff accepts up to 70% of the RS’s torque and then uses clutch units to lock the diff 50/50 to the rear wheels, creating the Drift mode that makes the RS so much fun to drive on a circuit.

Performance is likely to increase slightly, with the 0-62mph time dropping from 4.7sec to around 4.2sec. Top speed is expected to climb a little, to 167mph or so.