Romain Grosjean has hit out at F1 drivers who are not members of the Grand Prix Drivers' Association.
The Haas driver has just been appointed a director of the safety-oriented body, which is also led by president Alex Wurz and fellow GPDA director Sebastian Vettel.
But Grosjean said there are too many active drivers who are not members at all.
"Formula 1 is changing, and we as drivers could achieve more if we were a unit of 20 athletes," he told Speed Week.
"I think it's ok to have different opinions, but we must unite our sport. We all want more from Liberty and we can do that better if we speak with one voice."
Asked which F1 drivers are missing, Grosjean did not hesitate to pull out his mobile phone.
"I can tell you exactly who is not with us," he said.
"Hamilton, Bottas, Verstappen, Stroll, Massa, Wehrlein, Sirotkin, Celis, Raikkonen, Hulkenberg and di Resta," said the Swiss-born Frenchman.
"When I entered F1, I wanted to be a part of it right away. So I'm a little surprised that so many are not. We're working on it."
Win the ULTIMATE TRACKDAY with F1i.com!
GALLERY: All the action from Barcelona on Friday
Keep up to date with all the F1 news via Facebook and Twitter
Oliver Bearman got quite the early morning wake-up call on Friday in Sao Paulo when…
While his team mate Max Verstappen thrilled the fans with a run from 17th on…
Williams suffered a bruising time on Sunday in Sao Paulo, with Alex Albon unable to…
McLaren team principal Andrea Stella has insisted that the squad has no regrets about their…
On this day in 1989, Williams' Thierry Boutsen secured his second F1 win when he…
Red Bull team principal Christian Horner hailed Max Verstappen’s sensational Sao Paulo Grand Prix victory…