Lewis Hamilton says Formula 1's calendar is already too bloated and has suggested he could quit the sport if Liberty continue to add more grands prix to the schedule. Plans for a Vietnam GP to be introduced in 2020 were confirmed this week, while races in the Netherlands and Miami are also in the pipeline, with Liberty having previously suggested a 25-race calendar is on the cards.
The street race in Hanoi has split opinion among fans, while commercial chief Sean Bratches' suggestion that classic tracks like Silverstone may have to make way for the new venues has again caused consternation.
Hamilton says he would prefer an 18-race schedule – every season since 2010 has featured at least 19.
The freshly crowned five-time world champion says he won't stick around to see if he can hack a 25-race calendar, putting a dent in Liberty's expansion plans.
"It already feels like we are on race 25 this year, so I don't think that's a good thing personally," he said.
"I think 18 was probably the best back in the day.
"I'm someone who really loves racing but the season is long. It's a lot of commitment for all of us and a lot of time away from families and the seasons are getting longer and the off time is getting shorter. All I can speak is for myself.
"The turnaround is so short, you start preparing for your next season often as soon as the season is done.
"Getting your mind turned. That's very difficult. Then you have to find a way of switching off and recovering at the same time. It's most likely I'm not going to be here when it gets to 25 that's for sure."