Robert Kubica to test 2017 Renault in Hungary next week

Robert Kubica's return from life-changing injuries will take a step up when he drives a 2017 Renault at a test in Hungary on 2 August.

The 32-year-old Pole has not raced in Formula 1 since a horrific rally crash in 2011 left him with only partial movement in his right arm.

The test, Kubica's third for Renault, is described by the team as "a new phase in assessing [his] capabilities".

It will increase speculation about an impending - and remarkable - comeback.

Kubica has already done two tests in a 2012 Renault and has said that his physical limitations do not affect his driving.

But it cannot be certain that he can return until he has proved that is also the case in faster and more demanding 2017 machinery.

Renault F1 managing director Cyril Abiteboul said: "The first two days of testing allowed both Robert and ourselves to gather a great amount of information.

"The upcoming session with the RS17 at the Hungaroring will allow us all to obtain detailed and precise data in a current car and representative conditions.

"After this test, we will carefully analyse the collected information to determine in what conditions it would be possible for Robert to return to competition in the upcoming years."

The test in which Kubica is taking part is the official two-day F1 test on the Tuesday and Wednesday following this weekend's Hungarian Grand Prix.

It will enable Kubica's performance to be measured directly against other teams and drivers and with the immediate context of Renault's performance over the previous race weekend.

A source close to Kubica has told BBC Sport that "Robert is ready to come back at his level".

Should Kubica prove to be anything close to his former abilities, it would leave Renault with a difficult choice.

They have been considering replacing their second driver Jolyon Palmer for some time as the Englishman has lagged behind the performance of team leader Nico Hulkenberg this season.

If Kubica performs successfully in the Hungary test, the temptation to draft him in for the Belgian Grand Prix on 25-27 August after F1's summer break may be difficult to resist.

A return by Kubica would be one of the most remarkable comebacks in sporting history.

He suffered a partially severed right arm and multiple fractures in his rally crash in February 2011.

At the time, he was regarded as one of the brightest talents in the sport, a winner of the 2008 Canadian Grand Prix for BMW Sauber and considered to have similar levels of talent to superstars Lewis Hamilton and Fernando Alonso.

But the injuries curtailed his career on the eve of his second season with Renault, at a time when he was widely considered to have been lined up to join Ferrari as Alonso's team-mate in 2012.

He has spent the past six and a half years struggling to get his body into a condition where he can make a comeback to F1 and in the past few months believes he has finally done so.

He said after his most recent test on 12 July: "My doubts about my capacities have disappeared with these two days of tests. I am no longer afraid of not being at the level but there remains a way to go."

That final remark is said by sources close to him to be a reference to the fact that he has not yet driven a current car.