Mercedes team boss Toto Wolff has suggested that the world championship battle between Lewis Hamilton and Nico Rosberg will go down to the final race this season.
Hamilton surged into an early-season lead with three wins from the opening four races, but Rosberg has hit back with wins in Spain, Monaco and Austria to cut the gap to 10 points.
Hamilton won the 2014 title at the final race in Abu Dhabi, and Wolff thinks that this year's champion will have to do the same.
He told Sky Sports News: "Sometimes we had people saying 'has Nico surrendered?' and I was always repeating that he's mentally very strong and I have no doubt that the battle is going to go down to the wire.
"They are so close to each other performance-wise. It's my opinion, because there are no double points this year, it could be until the last race [before the title is decided]."
The next race is the British Grand Prix in two weeks.