Prices for the new range-topping electric estate start at £26,495 for Excite trim, while the Exclusive starts from £28,995 (post-grant).
The new 5 will be sold alongside the existing entry-level model, which is advertised with a 214-mile official range.
MG says the EV can be charged up to 80% in just 61 minutes from a 50kW rapid-charger or in 40 minutes from a 100kW rapid-charger.
A full charge can be completed in approximately 9.5 hours from a standard home charger.
“With the new longer-range model, we’re offering MG customers even greater value and flexibility from their EVs,” said MG marketing director David Pugh.
“With a full charge giving a WLTP-approved range of 250 miles and the ability to be rapid-charged to 80% in as little as 40 minutes, the MG 5 EV is a car that really can bring electric motoring to the masses, and it has played a big part in MG’s rapid charge ahead as one of the leaders in the UK EV market.”
MG also claims the 5 now offers the highest range-per-pound of any EV in the UK. It's aiming the model at the fleet market, with small and medium-sized businesses in mind.
The upgrade also brings MG's pilot advanced driver assistance feature, which includes a selection of warning and alert features, including automatic emergency braking, lane-keeping assistance and adaptive cruise control.
The new 5 also gets MG's seven-year warranty.