Both are plug-in hybrids and are available in both SUV and coupe-like body styles.
The GLC 300 e features a 2.0-litre petrol engine and a 13.5 kWh battery. The four-cylinder unit delivers 153bhp and 350Nm of torque, while the electric motor adds 120bhp.
It has an all-electric range of 29 miles and can deliver up to 117.7mpg and emit as little as 54g/km of CO2.
Mercedes also claims the model can be charged via a 7.4 kW wallbox in under two hours.
The GLE 350 de, on the other hand, makes use of a 2.0-litre diesel unit with 191bhp and 400Nm of torque, alongside a 134bhp 31.2kWh battery.
All-electric range is said to be 66 miles and the SUV claims to return up to 256.8mpg and emits just 29g/km of CO2.
In terms of charge times, the GLE 350 de is said to be able to charge from “10 to 100 per cent in 3.25 hours”, according to Mercedes.
The GLC 300 e 4Matic AMG Line starts from £49,687 (OTR), while the larger GLE 350 de AMG Line is priced from £61,360 (OTR). Both are on sale now, with deliveries set to begin in this summer.