Lewis Hamilton is worried he will prove to be his own worst enemy in the fight to claim his first Formula One world title.

The McLaren driver - who is level on 38 points with Ferrari's Felipe Massa - trails surprise Championship leader Robert Kubica by four points ahead of Sunday's French Grand Prix, with world champion Kimi Raikkonen a further three points adrift.

Hamilton would almost certainly be top of the standings had he not ploughed into the back of Raikkonen in the pit lane at this month's Canadian Grand Prix and the 23-year-old admitted the pressure was taking its toll.

He said: "There is so much pressure and I can't begin to explain how much of it I have on my shoulders.

"I put a lot of pressure on myself, too much, and that led to mistakes and being too much on the limit. When you don't succeed, it doesn't feel great and I wasn't enjoying it."

Hamilton has recovered well after a patchy start to the season, when errors in the Malaysian and Bahrain Grands Prix saw him fail to build on victory in Australia in the opening round.

But his chances of regaining the lead in the championship have been hampered severely by a 10-place grid penalty, a punishment imposed for his error in Canada that ended his race and Raikkonen's.

Hamilton, however, believes the difficulty of the situation can bring out the best in him.

He insisted: "These are character-building days and the days that make you stronger. I didn't win the last race but I get to come back here, work with the guys and push forward."