The FIA already said it would be more strict on exceeding track limits during the Belgian Grand Prix weekend last week, and they are to ramp up the penalties now, as lap times will be invalidated if track limits are exceeded.
Race director Michael Masi is not messing around!
Any driver that crosses the white track limit line with all four wheels will be in trouble. At the Parabolica, the long-winding right-hander which forms the final corner at Monza, drivers often go off track when exiting the corner onto the straight. However, if that happens now, not only will the lap be invalidated, but so will the lap after.
Masi is enforcing this punishment to prevent drivers from using the Parabolica to get a better line when heading into a flying lap.
Although the FIA's statement doesn't state what the in-race punishment will be should it happen on Sunday, but the logical conclusion would be that the penalty would be five seconds, since this is the penalty for leaving the track and gaining an advantage.