Williams have confirmed that the FW24 will not be built in time for Robert Kubica and George Russell to begin preseason testing on time next week in Barcelona. The British team are not the only squad reportedly struggling to get their machinery ready in time for testing.
The relatively late implementation of new aerodynamic regulations for the 2019 season has caught several teams out, with Renault and Racing Point also thought the be facing a race against the clock.
With one of the lower budgets on the grid, Williams have likely not had the personnel required to turn things around so quickly, while the likes of Red Bull and Mercedes have already built their 2019 cars and given them 'shakedown' runs on-track.
Williams' initial tests will come on Tuesday, 24 hours after the rest of their rivals may have started testing in earnest ahead of the season, putting last year's bottom-placed team at a disadvantage from the off this time around.
"Unfortunately, we have had to delay the start of our pre-season Barcelona test to Tuesday morning," deputy team principal Claire Williams said.
"We have had an incredibly busy winter at Grove getting the FW42 prepared for the season ahead and, despite everyone's best efforts, we need some more time before it will be ready to run.
"Our absolute priority is to always ensure we bring a car to the track that is the best that it can be and sometimes that takes longer than you'd anticipate or like. It's clearly not ideal, but equally it's not the end of the world.
"We will obviously have our work cut out to recover the time lost but we still have seven days of testing left and we will be maximising that time to prepare the car for the first race."