The 32-year-old Pole did a full day of running at the Hungaroring on Tuesday, six days after his one-day test at Silverstone in the same car.

It is part of a programme, which has also included Kubica spending time in the outfit’s simulator, to see if he is fit and ready to make a racing return next year.

Williams said Kubica "completed another productive day" but did not release any further details about his progress as the team "continues our evaluations".

The team’s reserve driver Paul di Resta will get one day of running in the FW36 on Wednesday, ahead of this weekend’s United States Grand Prix in Austin.

Williams is currently has a shortlist of four drivers - Kubica, Felipe Massa, Di Resta and Pascal Wehrlein - to fill the seat alongside Lance Stroll in 2018.

It is believed the team would like to make an announcement on its complete driver line-up before the end of the year.

Former F1 boss Bernie Ecclestone has said Williams should not hesitate to pick Kubica for next year as he is convinced the Polish racer can return to F1 better than he was before.

However, Massa believed Williams will go in a “much worse” direction if it does not retain him alongside Stroll for 2018.