On the eve of the first official FIA Formula E Championship test at Donington Park, just four seats remain available across the 20-car grid.

A flurry of recent announcements have swelled both interest and talent in the burgeoning project, which will see drivers from across motorsport participate in the first-ever all-electric single-seater world championship.

Of the 16 drivers confirmed so far - with the remaining four drivers expected to be announced shortly - nine have started F1 races, four more have undertaken F1 test driving roles and the remainder has enjoyed race winning success in junior series.

Of those, Jarno Trulli and Nick Heidfeld bring the most experience with 441 GP starts between them, while Lucas di Grassi, Sebastien Buemi, Karun Chandhok, Bruno Senna, Jaime Aluguersuari, Franck Montagny and Stephane Sarrazin also bring GP starts to the field.

In addition, Antonio Felix da Costa, Nicholas Prost, Sam Bird and Mike Conway have all had test driver roles, while Katherine Legge and Michela Cerruti bolster the female racer ranks in what is set to be a high-quality field lining up for the first time in Beijing on September 13th.

Meanwhile, Andretti Autosport and Dragon Racing are still to announce which drivers will join Montagny in the former and Conway in the latter, while the China Racing squad hasn't confirmed any drivers as yet.

The official Formula E test starts on Thursday 3rd July and will run for two days.

2014/15 FIA Formula E Championship - Grid line-up so far

Amlin Aguri
Antonio Felix da Costa
Katherine Legge

Audi Sport Abt
Daniel Abt
Lucas di Grassi

e.dams Renault
Sebastien Buemi
Nicholas Prost

Mahindra Racing
Karun Chandhok
Bruno Senna

TrulliGP
Jarno Trulli
Michela Cerruti

Venturi
Nick Heidfeld
Stephane Sarrazin

Virgin Racing
Jaime Alguersuari
Sam Bird

Andretti Autosport
Franck Montagny
TBA

Dragon Racing
Mike Conway
TBA

China Racing
TBA
TBA