Mercedes team principal Toto Wolff has admitted that an engine penalty for Lewis Hamilton cannot be ruled out at the Turkish Grand Prix this weekend.

Hamilton has used three engines so far this year, the maximum permitted for a Formula One car in a season.

Using a fourth engine would see Hamilton incur a penalty, starting at the back of the grid at the following race, and Wolff has said that is a “possibility” ahead of Sunday’s event in Turkey.

“When and how [a fourth engine is used] is not yet decided,” the Austrian said. “Most important is that you don’t DNF [‘did not finish’] because of a reliability issue.

“You can cope with swings. Whether you finish second, third, I think that is okay; the championship is going to go long. But if you don’t finish...

“So we are looking at the parameters of the engines, making sure we don’t suffer from any reliability problems.”

Hamilton leads Red Bull’s Max Verstappen by two points at the top of the drivers’ standings with six races left this season.

Verstappen is aiming to win his first F1 title, while defending champion Hamilton would go clear of joint-record holder Michael Schumacher if he were to emerge victorious come the end of the season.

Hamilton and Schumacher have each won seven F1 titles.