Available to order in the UK from early October will be the A250e in hatchback and saloon forms and the B250e MPV.
The two new variants are powered by a 1.3-litre four-cylinder petrol engine and an electric motor producing 101bhp. The EQ Power-badged powertrain’s combined output is 215bhp and 332lb ft.
A 15.6kWh lithium ion battery provides an electric-only range of between 35 and 42 miles on the WLTP test cycle, depending on bodystyle and options, and can be filled from 10-80% capacity in 25 minutes using a rapid charger.
A 7.4kW domestic wallbox will yield a full charge from 10% within 1hr 45min.
Performance changes over the standard A250 and B250 are minimal. The A250e will accelerate from 0-62mph in 6.6sec, 0.4sec slower than the lighter petrol variant. The B250e covers the same sprint in 6.8sec. Top speed is 146mph for the hatchbacks and 149mph for the saloon.
The new battery pack adds 150kg to the kerbweight of each car, but Mercedes says a rerouted exhaust system and repositioned fuel tank mean boot space is only slightly less than that of conventionally fuelled A-Class and B-Class models.
UK prices for the plug-in hybrids are yet to be confirmed, but an increase of roughly £3000 is expected over their petrol counterparts. The A250e hatchback will start from around £32,500, with an approximate £600 increase likely for the saloon, while the B-Class will start from roughly £33,800.