(Reuters) - Mercedes welcomed on Thursday a decision by Formula One's governing body to send them to a tribunal for allegedly breaking the testing rules and said they would explain the full facts "in an open and transparent manner".
"Sporting integrity is of primary importance to Mercedes-Benz and we have the utmost confidence in the due process of the FIA," the team said in a statement ahead of the Canadian Grand Prix.
Mercedes took part in what has been dubbed a 'secret' 1,000km test with tire supplier Pirelli in Barcelona last month, ahead of the Monaco Grand Prix won by their German driver Nico Rosberg.
The International Automobile Federation (FIA) announced on Wednesday that the matter had been handed to their international tribunal, who could impose stiff sanctions if Mercedes are found to have broken rules that ban teams from testing with current cars during the season.
Mercedes described it as a Pirelli test, and Rosberg - who took part in it with team mate Lewis Hamilton - said the Italian company were in complete control of the track activities.
"It was a full on Pirelli test - they dictate what we do," he told Britain's Sky Sports television.
"We have no say whatsoever - they say you are doing that, that, that and that and the engineers that they have run our program. So it is not for us to learn anything or to decide on anything that we do."
The question of who organized and ran the test is an important one.
Article 22.1 of Formula One's 2013 sporting regulations defines testing as any track running time that is not part of a regular grand prix weekend "undertaken by a competitor entered in the championship, using cars which conform substantially with the current Formula One Technical Regulations in addition to those from the previous or subsequent year."
Pirelli, as sole supplier to all 11 teams, are not a "competitor entered in the championship" whereas Mercedes are.
Ferrari, who also took part in a Pirelli test in April, were cleared of any wrongdoing on Wednesday because they used a 2011 car run by their customer division rather than the race team.
Pirelli motorsport director Paul Hembery said last week that champions Red Bull and Ferrari, who both protested the Mercedes test, had assured his company that "their claim is not against the tire test itself".
The FIA said in a statement after the Monaco race that "Pirelli and Mercedes-AMG were advised by the FIA that such a development test could be possible if carried out by Pirelli, as opposed to the team that would provide the car and driver."
It added, however, that "such tests would be conditional upon every team being given the same opportunity to test in order to ensure full sporting equity."
Pirelli have said they chose the date of the test, booked and paid for use of the circuit with procedures defined and determined 100 percent by them.
"It was a Pirelli test, performed to our standards and to our regulation and to how we wanted it done," Hembery told reporters last week.
Mercedes are likely to compete in the next couple of races with the matter hanging over them. The independent Tribunal, whose members are elected by the FIA general assembly, is unlikely to hear the case before mid-July.
Mercedes, who have maintained they had FIA approval for the test, will have at least 15 days to submit their own observations once they have been notified of charges.
The prosecuting body then has a further 15 days to respond, with another 15 days elapsing before any hearing, although the tribunal president can reduce or extend the time limits.
(Reporting by Alan Baldwin in London, editing by Ed Osmond)