By Alan Baldwin
LONDON (Reuters) - Seven of Formula One's 10 teams put on a rare show of unity on Wednesday in threatening legal action against a confidential settlement between the governing FIA and Ferrari over the Italian team's 2019 power unit.
The teams -- all those not powered by Ferrari engines -- said they had been "surprised and shocked" by an FIA statement issued at the end of the final day of pre-season testing in Spain last week.
That FIA statement provided little information, other than stating that the governing body and Ferrari had reached a settlement after technical investigations into the team's engine.
It said "the specifics of the agreement will remain between the parties", a position that raised questions about why the statement had even been issued.
The seven teams, including champions Mercedes, made clear in a joint statement that the situation was not acceptable, with the sport preparing for the first race of the season in Australia on March 15.
The non-signatories, apart from Ferrari, were Haas and Alfa Romeo who are closely aligned with the Italian team.
"An international sporting regulator has the responsibility to act with the highest standards of governance, integrity and transparency," the seven teams said.
"After months of investigations that were undertaken by the FIA only following queries raised by other teams, we strongly object to the FIA reaching a confidential settlement agreement with Ferrari to conclude this matter."
The teams added that they had a shared commitment "to pursue full and proper disclosure in this matter, to ensure that our sport treats all competitors fairly and equally".
"In addition, we reserve our rights to seek legal redress, within the FIA's due process and before the competent courts."
Ferrari's engine was the subject of much speculation last year, with rivals suspecting the team were circumventing fuel flow sensors to gain performance.
Red Bull's Dutch driver Max Verstappen angered Ferrari by suggesting last November that they were bending the rules. In one interview with Dutch television, the 22-year-old used the word "cheating".
Verstappen was more diplomatic on Wednesday after doing the first lap of the revamped Dutch GP circuit at Zandvoort.
"The answers I will leave up to the team, I'm not involved in that," he told Sky Sports television. "But I think in every sport you want a level playing field."
Ferrari, who denied doing anything illegal, had started the 2019 season as early favorites after impressive times in testing and a clear straight line speed advantage.
The performance appeared to tail off, however, after the FIA issued several technical directives concerning fuel flow sensors later in the year. They have also been slower than Mercedes on the 2020 testing timesheets.
Ferrari team principal Mattia Binotto said in December they had been one of the most checked teams on the grid and had not changed their way of operating the engine towards the end of last season.
Ferrari finished runners-up to Mercedes in 2019, with three race wins.
Formula One managing director Ross Brawn, a former Ferrari technical director as well as ex-principal of Mercedes F1, could not shed any light on the settlement when asked by Reuters on Tuesday.
"I don't know and there's nothing I can say," he replied.
(Reporting by Alan Baldwin; Editing by Pritha Sarkar and Ed Osmond)