TOP grand prix teams Williams and McLaren have threatened their rivals with legal action unless they and Tyrrell are readmitted as signatories to the Concorde agreement, enabling them to claim their full share in the huge television income generated by the F1 world championship.

They have set a deadline of March 26th for the other seven signatory teams - Ferrari, Benetton, Prost, Arrows, Jordan, Minardi and Sauber - to agree to their inclusion on equal terms, otherwise the matter may have to be settled by a costly and protracted court case.

Williams, McLaren and Tyrrell originally stayed outside the Concorde agreement when it was renewed at the start of this season because they were not satisfied with the share of television revenues being offered to the teams by Bernie Ecclestone's FOCA TV organisation.

Although the seven signatories will receive substantially increased television income in 1997, the dissenting trio believe this is a relatively small bonus compared with what Ecclestone's company stands to earn during its recently renewed 15-year licence to manage the FIA's television rights.

"They had the chance to sign on the same terms as everybody else, and chose not to," said Ecclestone last week. "It's a bit like having the chance to buy gold at $400 an ounce, then complaining that it's gone up to $500 and wanting to buy it at the old price. Having said that, I think all the other teams regard it as a silly situation which they would like resolved."

However, readmitting these teams will require the existing seven signatories either to agree to a reduced share in the television revenues - or Ecclestone to volunteer a larger slice of the TV cake.

Jordan driver Ralf Schumacher posted the fastest lap at new-look Silverstone during two days of testing. Schumacher completed the resurfaced circuit in one minute 21.44 seconds. This compares to Jacques Villeneuve's quickest lap of 1:29.288 during last year's British Grand Prix.