ABU DHABI, United Arab Emirates (AFP) — An irate Toto Wolff slammed his own Mercedes team on Saturday for an "inexcusable" decision that led to seven-time champion Lewis Hamilton flopping in qualifying at the Abu Dhabi Grand Prix.

Wolff blamed "an idiot’s mistake" that led to Hamilton being sent out late to ensure he reached the second qualifying session when an errant bollard lodged under his car and wrecked his performance and lap.

As a result, he will start towards the rear of the grid for his final race with Mercedes before joining Ferrari next season.

"I just need to apologize to Lewis," Wolff said.

"And also to everyone in the team that worked so hard in making it a great end for him. He was the quicker guy with the set-up we chose.”

"We totally let him down. An idiotic mistake not to go earlier. Inexcusable, inexcusable! I’ve rarely been so down about what has happened.”

"Maybe it summarizes the last races we’ve had with him, but this is the worst part of it because it was just idiotic."

Hamilton had been fastest earlier in the third and final practice session, prompting hopes that he would leave Mercedes with a podium finish at a circuit where he has claimed a record five pole positions and five wins.

"Maybe without the bollard, it would have worked. You don't risk so much in Q1, where we easily had the pace to make it out there.

"Our most valuable racing driver ever, the most valuable, greatest driver of this sport goes out in Q1 because we make a mistake.”

"It doesn’t ruin the legacy we have, but I can only say sorry to him."

"What happened is absolutely inexcusable. Inexcusable… Lewis is with us for the last race and we’re going to be clever and then try to come out last.”

"It’s simple. We wanted to do so well for him this weekend and then it's really due to an idiot's mistake. You don’t have to — you have to be human. You have to play it safe and no look like you’re super clever."