Ferrari have threatened to throw Formula One into chaos by contesting the results of Grands Prix already run this year.
McLaren are one of the teams testing new Michelin tyres this week
The Italian team, who use Bridgestone tyres, say they believe rivals Williams and McLaren have been using illegal tyres supplied by
Michelin that pass pre-race controls but are illegal during the race.
"There is a facility within the regulations to investigate any matter if previously unknown information becomes available," Ferrari technical director Ross Brawn told Autosport magazine.
"It's not what we want but Ferrari are very angry and frustrated as it is now clear that a large number of the Michelin teams were running illegal tyres for a considerable amount of time - and we don't know for how long yet."
He added: "Measurements were taken after the Hungarian race [last month] that clearly showed that there were tyres above the legal limit and we've got to see what develops because we're not happy with that situation."
The title race is finely poised, with Ferrari's Michael Schumacher one point ahead of Williams driver Juan Pablo Montoya and two in front of Kimi Raikkonen of McLaren.
A protest would likely result in the championship being decided in a courtroom rather than out on the track.
Michelin says its tyres have been passed legal by the sport's governing body, the FIA, which has issued a ruling since Hungary saying there will be new checks on tyres after races to ensure teams are not using more than the permitted maximum tread width.
The French company is believed to have been using the same design of tyre since the San Marino Grand Prix in April without any previous problems.
But Michelin has built new tyres for the forthcoming Italian Grand Prix at Monza in an attempt to avoid any further controversy. These are being tested at Monza in Italy this week.
Michelin contends that the FIA's "clarification" amounts to a rule change and as such should have been delayed until next season.
Many within F1 believe the new tyre ruling has been introduced to help Ferrari's faltering title hopes.
Williams technical director Patrick Head told the Guardian: "As I understand it, the entire specification and dimensions of the Michelin tyre was submitted to the FIA for approval.
"I might add that Ferrari have always proved as adept in Formula One political matters as they have in terms of their competitiveness on the track and have been very effective in lobbying for changes which work in their favour.
"But perhaps that's all part of the F1 business and maybe you need to be able to do that."
Brawn (centre) insists Ferrari are not damaging F1
Brawn rejected suggestions that the FIA's move was damaging to the sport.
"This was an attempt by Michelin to circumnavigate the regulations," Brawn said.
"It would be wrong if a car won the championship which had been blatantly using illegal tyres. That is not right.
"It devalues the competition and we must not allow people to win championships when they are contravening the regulations."
Others argue that changing the rules in the middle of the season would also devalue the championship by bringing into question the results of all previous races.