Williams have revealed in a statement today that it now looks unlikely that the team will be in a position to perform testing on Tuesday, along with the other teams at Circuit de Catalunya.
Earlier, on Sunday, Williams noted they would not be testing on Monday.
Though the new car did arrive at Barcelona on Monday morning, Deputy Team Principal Claire Williams has now cast doubt over the car's debut.
"It is looking more likely than not that we will now not be in a position to run on track until Wednesday at the earliest. This is obviously extremely disappointing, but it is unfortunately the situation we are in. We will be getting the FW42 on track as soon as we are able."