The FIA's international court of appeal met behind closed doors in Paris in a case that will determine whether third place stays with Alpine's Pierre Gasly or goes to Red Bull's Isack Hadjar, with knock-on effects for others immediately behind.
Gasly finished third on track on June 7 but was demoted to seventh when two five-second penalties for pit-lane speeding were applied post-race, with fellow Frenchman Hadjar promoted to third and spraying the champagne.
That decision was overturned after a right to review on June 12, stewards accepting Renault-owned Alpine's evidence that there had been a timekeeping error. Hadjar then handed the trophy back to Gasly before his team and McLaren appealed on June 16.
As well as Hadjar dropping down, in a race won by Mercedes' championship leader Kimi Antonelli with Ferrari's Lewis Hamilton second, McLaren's Oscar Piastri moved down to fifth, with Liam Lawson sixth and Arvid Lindblad seventh for Red Bull-owned Racing Bulls.
McLaren team boss Andrea Stella said at the weekend's Dutch Grand Prix that the removal of Gasly's penalties raised significant elements of concern from a position of fairness.
Piastri penalties
Piastri also got penalties for the same speeding offence but he, unlike Gasly, served them during the race - a situation that could not be overturned and cost the Australian places and points.
Mercedes driver George Russell, a title contender, finished out of the points after serving a drive-through penalty for pit-lane speeding. He said that he had pleaded for his penalty to be added post-race to retain a chance of it being overturned.
"There's a general interest for Formula 1 and the sport and the integrity of the sport, and there's a material interest for McLaren in terms of our championship impact," said Stella of McLaren's reasons for appealing.
Stewards noted when Gasly's penalties were overturned that the situation was unfair to others.
"There is no regulation that gives the stewards the power to 'undo' a served penalty. In any case, it is impossible to imagine how such power could be applied," they said at the time.
No details emerged from Tuesday's confidential hearing.
Formula 1's next race is the Italian Grand Prix in Monza on September 6, followed by the debut of Madrid's new circuit on September 13.