Barcelona: Triple world champion Lewis Hamilton blasted Formula One as "broken" and "lacking in direction" as the sport's bosses debate a range of changes to regulations.
The Mercedes star believes that tinkering with the qualifying format, which has caused splits in the paddock and amongst fans as the world championship tries to boost its appeal, is detrimental to the sport.
The autosport.com website and BBC reported that when asked if Formula One is "broken, lacking direction, or in rude health?", Hamilton replied: "I would probably say the first two you suggested."
But Hamilton then added: "I don't want to say too much, but I do agree with the first two things you said."
The Briton, speaking on the penultimate day of pre-season testing in Barcelona, also took aim at the new cockpit safety system, known as the "Halo".
The three-pointed carbon structure is placed at the front of the car and is intended to prevent more driver fatalities.
"Please no! This is the worst looking mod (modification) in Formula 1 history. I appreciate the quest for safety but this is formula 1, and the way it is now is perfectly fine," Hamilton wrote on his Instagram page.
The Halo was tried on track by Ferrari's Kimi Raikkonen on Thursday.
Demands to increase driver safety have intensified following the deaths of Jules Bianchi and IndyCar driver Justin Wilson last year.
Hamilton's Mercedes teammate, Nico Rosberg hailed the device as a "massive safety improvement".
However, the father of former F1 driver Bianchi, who died after colliding with a recovery vehicle at the Japanese Grand Prix in 2014, claimed the new measures don't go far enough.
"This is a step forward, but it does not solve everything," Philippe Bianchi told Canal Plus.
"In the case of Jules it would not have changed since it was the extremely violent deceleration that we know caused the damage to his brain.
"The version of this Halo system I saw this morning did not convince me and still needs to be improved."
Raikkonen used the structure on his installation lap on the third day of the second pre-season test in Barcelona before going on to set the fastest time of the winter once it was removed.
The Halo won't be used for the upcoming season which starts at the Australian Grand Prix on March 20, but a meeting of the F1 Commission last week approved measures aimed at introducing it for the 2017 season.
However, Rosberg was the most demonstrative voice urging for the Halo to be passed into the sport's laws.
"My opinion is that it represents a big step forward in terms of safety," said the German.
"Following the fatalities we have experienced in recent years in racing that halo would have saved lives, so we absolutely need it."
However, the Halo's aesthetic appearance as well as its ability to protect drivers was criticised.
"That looks even worse than I feared, in several respects," former F1 driver and pundit Martin Brundle tweeted.
Ferrari, though, insisted the final version of the prototype would be more visually pleasing.
"This is a provisional structure made by Ferrari to test visibility," a Ferrari spokesperson told Sky Sports.
"We think the final structure would be part of the car and hopefully will look better. Kimi said it was 'okay' in terms of visibility."