Formula 1 world championship leader Max Verstappen of Red Bull and Ferrari rival Charles Leclerc will start Sunday’s Belgian Grand Prix with engine damage.
The governing FIA said both pilots exceeded the permitted use of engine components, triggering automatic penalties.
McLaren’s Lando Norris, Alfa Romeo’s Valtteri Bottas and Alpine’s Esteban Ocon will also miss the grid for the same reasons, while Haas driver Mick Schumacher has a 10-place penalty.
The penalties will increase the chances of seven-time Mercedes champion Lewis Hamilton and team-mate George Russell to take their first win of the season.
Ferrari’s Carlos Sainz and Red Bull’s Sergio Perez will also fancy their chances, with their teammates likely to start well behind them.
After 13 of 22 races, Verstappen leads nearest rival Leclerc by a huge margin of 80 points.