Ross Brawn believes the future of Formula One depends on teams in the midfield challenging big-hitters Mercedes, Ferrari and Red Bull in the coming seasons.

The 2018 campaign saw those three teams lead the way in the constructors' championship, with a 297-point gap from Red Bull to next-best Renault, while seventh-placed Nico Hulkenberg trailed future team-mate Daniel Ricciardo in sixth by 101 points in the drivers' standings.

And this lack of competition has been evident in each individual race over the last two seasons, as only Lance Stroll, at Azerbaijan in 2017, and Sergio Perez, at Azerbaijan in 2018, have reached the podium.

F1 director Brawn is concerned that the chasm between the elite and the rest is detrimental to the sport.

"They were practically racing in their own championship, with far too big a performance gap between them and Mercedes, Ferrari and Red Bull," Brawn said of the midfield.

"As was the case in 2017, only once and, significantly, on a very unusual street circuit like Baku, did a driver from one of those seven teams make it to the podium. Last year it was Lance Stroll in the Williams, this time it was Sergio Perez for Force India.

"Two podiums from a total of 123 is unacceptable, especially when it comes with an ever increasing technical and financial divide.

"It's a problem we are tackling together with the FIA and the teams, because the future of Formula One depends on it. There are various solutions on the table and we must all accept that we can’t go on like this for too much longer."