Despite claims of a radical new design direction beginning with the Mk4 Leon, the test mule shows an evolutionary look. Seat is gradually moving away from straight edges and sharp angles for future models, and this mule’s curvier front-end demonstrates that.

The C-segment car will get a more advanced infotainment system – which can update maps, apps and functionality over the air – similar to that offered in the Mk8 Volkswagen Golf. Seat CEO Luca de Meo said: “For two years, we have been working on what will be the best infotainment system coming to market next year, starting with the Leon.”

Along with the new cabin tech, the fourth-generation Leon will also be available with Seat’s first plug-in hybrid powertrain to offer improved fuel economy as well as limited zero-emissions running. The plug-in Leon is billed as the model to kick-start Seat’s electrification ambitions, which will gain pace when its first truly bespoke EV, the El Born, is launched in 2020.

New Cupra Leon ST hot estate seen ahead of 2020 launch

To signify its big stride forward, the upcoming Leon’s look has been described by brand design boss Alejandro Mesonero as taking “a bigger step” than the company has taken since the relaunch of the brand with the current Leon in 2012. “Sometimes you need to take a bigger step so as not to be obsolete. We’re ready very soon for the next, bolder step in design,” he said.

Rabe has previously told Autocar that the design and packaging of the five-door car will “not be a typical hatch” and that “it will create some desire”. 

The next Leon will once again use the VW Group’s MQB platform, albeit a significantly updated version shared with the recently launched Mk8 Golf.

The Leon will come in five-door hatch, estate and crossover forms. The latter, jacked-up version will sit below the Ateca SUV in the brand’s range and be “more extreme” than the previous version of the Leon estate, according to Rabe. He added: “We talk about hatch and we talk about SUV. Why not make something in-between?” 

The range is expected to open with the familiar 1.0-litre TSI three-cylinder petrol engine, offering similar performance to today’s model. 

Seat won’t drop diesels from the line-up, Rabe said, but the range will include one of the first mild-hybrid petrol options within the VW Group for those wanting levels of economy similar to those offered by oil-burning engines. This is likely to use the 48V system mated to a 1.5-litre TSI engine, as found in the Golf.