Ferrari team boss Mattia Binotto feels "ashamed" Formula One did not agree on a change to the specification of this year's tyres that could have helped curb Mercedes' dominance this season.
Mercedes is the only team that has consistently got this year's Pirelli tyres to work, while Ferrari and Red Bull have struggled to keep them in the right temperature range. That contributed to Mercedes winning the first eight races of the 2019 season before Max Verstappen took the first non-Mercedes victory since the 2018 Mexican Grand Prix at Sunday's Austrian Grand Prix.
A particularly dominant Mercedes victory two weeks ago at the French Grand Prix fuelled concerns that the sport had become too one-sided and led to a proposal from Ferrari and Red Bull to change the tyre specification in an attempt to slow Mercedes down. The idea was to go back to 2018-style tyres that had a thicker tread and were easier to keep up to temperature.
However, the thicker tread also means the tyres are more prone to overheating -- one of the main complaints from drivers last year -- which is exactly why Pirelli reduced the tread by 0.4 millimetres this year.
A vote was held at the Austrian Grand Prix over whether F1 should switch back to 2018-spec tyres this year, but it required the support of seven teams to be approved and only received the backing of five. As a result, F1 will stick with the existing 2019-spec tyres for the rest of the season -- a decision Binotto regrets.
"I think it has been a good battle in Austria, and normally you have good battles when you do not have one team which is overperforming," he said. "This weekend has been great in that respect.
"But I think we missed a great opportunity this weekend on the tyres decision. I think F1 as a whole should have done something and I think sometimes we are discussing and not acting.
"I feel really ashamed that we didn't change the specification of the tyres for the rest of the season because that would have been a great opportunity to somehow close the field."
However, there were a number of potential issues with reverting to 2018-style tyres -- not least a return to the overheating problems teams experienced last year. Pirelli counted 23 blisters on tyres across all teams at this year's French Grand Prix despite using the reduced tread and believes the problem would have been far worse had it used 2018-style tyres.
"For me it's very strange," Pirelli motorsport boss Mario Isola said. "I don't see any real advantage to go back to 2018 tyres and I explained that on a technical side [at the vote].
"Last year, the main complaints were blistering but in the second half of the season, with the improvement of the car it became even worse towards the end of the year. Overheating is a hot topic for drivers, and so we developed a product this year that is in in line with their request and now we have a tyre that has less overheating.
"The blisters we had in Paul Ricard are not dangerous, but it is telling us that the current cars are very fast and putting a lot of energy through the tyres. So, if we got back to last year's tyres we have more blistering, more overheating, drivers that cannot attack and cannot push, so the show could be even worse! That was my consideration.
"Then we can discuss if this change would change the balance of performance across the teams. I have an opinion on that, but the technical facts are that it will increase overheating and increase blisters."
The other problem is that the 2018 tyres were never tested with 2019 cars, so Pirelli would have needed to test the change before signing off on it from a safety perspective. The actual proposal was to use 2019 compounds with thicker tread, essentially creating a completely new hybrid tyre.
What's more, the change could not be introduced immediately as the sporting regulations specify certain lead times to allow Pirelli time to manufacturer the tyres and transport them around the world. Tyre selections have to be announced eight weeks ahead of European races and 14 weeks ahead of flyaway races to allow for the logistical challenge of shipping 13 sets of dry tyres per car (plus spares) across the globe.
As a result, the earliest the 2018-style tyres could have debuted after being tested in Austria this week would have been the Italian Grand Prix, but because the following two rounds are flyaways in Singapore and Russia, the 2019-spec tyres would have returned for those two rounds. It then would have been possible to use the 2018 tyres again for the last four rounds in Mexico, U.S.A., Brazil and Abu Dhabi, but by that point it is likely the championship will have already been decided.
One compromise solution being discussed is to race Pirelli's 2020 development tyres from the U.S. Grand Prix onwards, but that would require a change to the sporting regulations as prototype tyres can only be used during Friday practice under the existing rulebook.
"In the regulations we have the possibility to bring two sets of an additional prototype during any event, but they have to return these prototypes after FP2," Isola explained. "So basically they use the tyre to clean the track because they don't have any incentive to understand these tyres because they are not going to use them during a race or qualifying.
"To use the tyres in quali or during the race, we need a modification of the sporting regulations and to have that you need unanimity. How possible is it to implement that? We are available to do that but it is necessary to better define the idea because you need to find the wording to write a draft regulation, submit it to the teams and approve it and if you want to do something you have to do that very quickly."