Ferrari boss Jean Todt has denied accusations that his team betrayed rival teams by testing last week.
A long-held agreement by the teams bans testing in the week of a race and a statement signed by eight teams accused Ferrari of contravening the deal.
But according to Todt, the agreement is no longer valid after changes were made to it without Ferrari's consent.
He said: "We denounced the agreement, there is no more agreement. We are not part of the new agreement."
The only team not to sign the statement accusing Ferrari was Sauber.
Elsewhere, Ron Dennis has defended McLaren's right to use a third car on Grand Prix weekends.
Teams can use a third car if they finish outside the top four in the Championship, a scheme introduced to help the smaller outfits.
McLaren finished fifth in the championship so are entitled to run a third car, but the sight of a powerful team like McLaren clocking up vital laps last Friday led to some rivals calling for an end to the idea.
But McLaren boss Dennis said the team were within their rights.
"Under the regulations we are entitled to run a car and we feel comfortable doing it"
"The reality is that the teams unanimously agreed to the process.
"We are not exploiting anything that doesn't exist in the rules."
He added: "If we went into the last grand prix and we were in a position that would put us fourth in the points, we would have done it.
"We are not proud of our 2004 performance.
"Equally if we are out of the top four, under the regulations we are entitled to run a car and we feel comfortable doing it," he said.