The FIA is poised to start checking the legality of controversial suspension systems fitted to some 2017 cars.
Earlier, as Ferrari in particular press a case against the legality of Mercedes and Red Bull-like active suspension-mimicking concepts, it emerged that F1's governing body had issued a new rules clarification.
However, Auto Motor und Sport reports that teams will be invited to actually demonstrate the legality of their layouts to the FIA on the final day of the first Barcelona test on Thursday.
"The clarification is a basis for the stewards in disputes," an FIA source is quoted as saying. "Whether a suspension is in conflict with that clarification will then be [decided] on a case-by-case basis."
It is rumoured that at least one team - apparently Red Bull - have already been asked to change their design.
"Everyone can use what they want," said FIA race director Charlie Whiting. "But it would be foolish to test something which cannot be used in Melbourne."
Until now, Mercedes and Red Bull have been saying that the FIA is happy with their intended designs, but Whiting explained: "The teams asked us if we are satisfied with the function of certain components and we answered yes or no. Now they have to prove it to us."
The new championship begins later this month in Melbourne.
