Prices for the French firm’s Volkswagen Golf rival start at £29,495 for the Iconic trim level, while the premium RS Line starts at £31,495.
The Mégane hatchback loses its petrol and diesel powertrains, gaining a plug-in hybrid option in line with Renault's electrification strategy.
It joins the Mégane Sport Tourer estate in the firm’s electrified line-up, and Renault says it's capable of a combined WLTP fuel economy of 235mpg and CO2 emissions of just 28g/km, with a potential electric-only range of 30 miles.
Both the Iconic and RS Line are driven by a 1.6-litre petrol engine and a 65bhp electric motor for a combined output of 158bhp, sending the Mégane from 0-62mph in 9.4sec and up to a top speed of 114mph.
An electronic parking brake, cruise control, a 10.0in digital information display and eight ambient lighting colours are standard on both trim levels.
The Iconic receives 16in alloy wheels, a leather steering wheel and smartphone integration with Apple CarPlay and Android Auto. That's in addition to front and rear parking sensors, hill-start assistance and Renault's Visio System as standard, which includes lane-departure warning, traffic sign recognition and automatic high and low-beam.
The RS Line gains exclusive body-coloured sporty bumpers, 17in alloy wheels and a leather-wrapped sports steering wheel as standard, plus automatic emergency braking, a rear parking camera with hands-free parking and a larger (9.3in) touchscreen infotainment system.
The Mégane PHEV will use the same technology found on the Clio E-Tech hybrid and starts in EV mode by default. It's equipped with a 9.8 kWh battery which can be charged from 0-100% in only three hours using a Type 2 charger or four hours and 15 minutes using a domestic three-pin plug socket.
“When combined with the other hybrid and 100% electric vehicles in the Renault passenger car range, the addition of the Megane Hatch Plug-In Hybrid means Renault now offers an electrified option to suit everyone,” Renault said.
Orders will be taken from August ahead of customer deliveries getting under way in September.