Toto Wolff admits lacklustre performances in Monaco and Baku have left him experiencing his “toughest” period as Mercedes Formula 1 boss, calling its recent form “not acceptable”.

Mercedes suffered difficult weekends on both street circuits, scoring just seven points from a possible 88 that has allowed Red Bull to pull away in both championships.

Having lost a potential podium in Monaco after Valtteri Bottas’ bodged pitstop and a poor strategy failed to aid Lewis Hamilton’s progress through the field, Mercedes’ woes continued in Baku.

Mercedes was a second off the pace on Friday before a drastic turnaround in qualifying saw Hamilton secure a place on the front row. But in the race Bottas struggled to 12th, while Hamilton missed out on victory after accidentally hitting the wrong button on his steering wheel at the restart resulting in a lock-up.

A frustrated Wolff believes Mercedes has underperformed at the last two rounds, urging his team to get back to its “A-game” at the French Grand Prix.

“I think there’s lots of things that are not running smoothly as they have in the past few years,” said Wolff, as quoted by Motorsport.com.

“Operationally we are not at our A-game. We haven’t found really the sweet spot of the car through qualifying and race, of having a quick qualifying car and a quick race car.

“There’s just so much that we need to improve, that I just want to get on it right now, after this call, in order to make sure that we are actually able to compete for this championship.

“You can’t continue losing points, like we’ve done in Monaco and here. It is just not acceptable for all of us.”

Wolff said having to deal with the disappointment of Monaco, plus its struggles in Baku, has faced him with his biggest challenge since joining Mercedes in 2013.

Asked if these were the hardest weeks he could remember as Mercedes team principal, Wolff said: “Yeah, they are the toughest. Because not having performance in Monaco, and Valtteri, who would have made it solid on the podium, needing a pitstop of 36 hours, is not really a great achievement, based on the standards that we’re setting ourselves.

“Then the car that was almost all sessions [in Baku] nowhere. Then, to be honest, cruising in third and even trying to make it was okay.

“But it’s just not acceptable that we are not getting the car into a performant position after the start, or out of the pitstops. It’s just we’re losing seconds over seconds.”

Max Verstappen’s retirement in the closing stages meant the championship remained unchanged, but Wolff said Hamilton’s error and its poor display in Baku was particularly tough to take.

“Both of us are destroyed, to be honest,” said Wolff. “For him obviously, as a driver, you have it, it’s so close, and then it’s all gone.

“We just need to be the best, the best of us, and the best that we have. And we haven’t given the drivers a competitive package this weekend. It’s been far from a competitive package.

“That is the frustration. It is not only the incident at the end, that frustrates. It’s overall not meeting our own expectations. All of us together: Lewis, the engineers, myself, everybody in the team.”