Lewis Hamilton has urged his Mercedes team to rectify a reoccurring mechanical problem that has struck for the second event in succession.

The reigning world champion will start Sunday’s Russian Grand Prix from 10th on the grid after a power unit failure ruled him out of the final part of qualifying.

Mercedes has since identified the issue to be identical to the problem suffered by the Brit at the Chinese Grand Prix, which saw him start from the back of the grid.

Hamilton admitted he felt ‘helpless’ by his run of mechanical issues and is eager for his team to find a solution.

The 31-year-old suffered the added blow of receiving a reprimand following qualifying for failing to obey directions for rejoining the track at Turn 2.

Having been reprimanded twice already this season, a further warning will see him issued with a 10 place grid penalty.

“I’m very, very curious as to what is going on so I’ve asked them (the team) to give me as much detail as possible,” said Hamilton.

“We did 800kms a day in testing. The car was faultless, and all of a sudden two times in a row, the same thing. That doesn’t happen for us.

“We learned, or they say that we understood what happened in the (last) race, and I thought we would have learned from that, but obviously not, and more work needs to go in.

“Now we’ve got another engine going in, and who’s to know it’s not going to happen on that one?

“What’s really key is that we understand what it is, more so than we did before, and try and be careful on how we take out all the engines that we have for the rest of the year.

“Obviously I now have only three for the rest of the year really, so I’m going to have another penalty later on in the year at some point. But I’ll do the best job I can.

“I don’t know what the word is, I can’t really describe how I feel. You’re almost helpless at some points.

“We worked so hard, my engineers and my mechanics, we’ve worked so hard to get the car in a great position this weekend, we had the great pace once again, and then this happens for us unexpectedly.”

Despite this latest blow to his title defence, Hamilton says the battle for the championship is far from over.

“I’m not really thinking of that at the moment. There’s still a long way to go. Once again, always trying to turn the negatives into positives,” added Hamilton.

“As I said in the last race this is another big challenge, and the challenge is becoming greater. Every challenge is an opportunity to rise, as I said. I quite like that approach, and I like that idea.”

Hamilton is 36 points adrift of Mercedes team-mate Nico Rosberg who will start the Russian Grand Prix from pole position.