The America's Cup regatta director Iain Murray has threatened to scuttle the competition unless his safety recommendations are upheld by the Cup's international jury.
Two of the challengers, Team New Zealand and Luna Rossa, have protested Murray's recommendation regarding rudder elevators.
The jury is scheduled to meet next week, a day after the first challenger race between the New Zealanders and Italians.
The proposed change to the rudder is one of the many recommendations proposed following the death of Artemis crew-member Andrew Simpson.
The San Francisco Chronicle is reporting that if the jury agrees with New Zealand and Luna Rossa, Murray will go back to the Coast Guard, which issued a racing permit this week, and say he doesn't think the racing would be safe.
In that case, the Coast Guard would almost certainly withdraw its permit.