The fifth and final model in the all-new Mini line-up will be an all-electric version of an existing model when it launches in 2019.

LATEST: Oxford confirmed as home for 2019 electric Mini production. Click here for more.

Mini boss Peter Schwarzenbauer has previously spoken of his desire to trim the Mini range to five models, which he describes as "superheroes". The three and five-door hatches are considered one superhero, the Convertible, Clubman and Countryman being three more.

There has been mystery around the fifth, with speculation suggesting that it could be a production version of either the well received Rocketman or Superleggera concepts, but Schwarzenbauer has now confirmed to Autocar that the fifth 'superhero' will be an electric car, throwing further doubt on the prospects of either of those models ever making production.

Schwarzenbauer wouldn't confirm what sort of model the electric car would be, but he did say it would be a version of an existing Mini rather than an all-new car.

The 2019 launch date is significant, because Schwarzenbauer said there would have been a breakthrough in battery technology by then to allow the model to be far more usable than existing electric cars.

"It's completely new technology," said Schwarzenbauer. "It's the next step in battery tech. We chose to launch in 2019 as this is when we will see the technology." He added he believes electric technology is the perfect fit for the Mini brand because of its urban roots.

Schwarzenbauer admitted that the decision to make the electric car the fifth Mini 'superhero' model made the "likelihood of doing [the Rocketman and Superleggera] a little bit less now". He added: "The focus is on the all-electric Mini", but did not formally rule them out of ever making production.

Before the 2019 launch of the electric Mini, the firm will launch its first plug-in hybrid (PHEV) next year in the form of a Countryman variant. Mini has previously experimented with an electric car with the 2009 Mini E research vehicle that was leased for trials, the feedback from which went towards the development of the BMW i3.