Mercedes Formula 1 boss Toto Wolff says the “potential for carnage” at the start of the Mexican Grand Prix leaves him nervous with both world championships on the line.

Lewis Hamilton will win his fifth world title with a top-seven finish in Mexico, while Mercedes has an outside chance of wrapping up a fifth consecutive constructors' world championship.

Hamilton starts third behind the Red Bull duo and will line-up alongside title rival Sebastian Vettel on the second row, while teammate Valtteri Bottas is just behind in fifth having split the Ferraris in qualifying.

Wolff fears the nature of the opening sequence of corners at the Autodromo Hermanos Rodriguez has the potential for drama - as seen in 2017 when Hamilton and Vettel clashed after running three-abreast with Max Verstappen into Turn 1.

“The grid has the potential for carnage on the straight and through the first corners,” Wolff said.

“You have the two Red Bulls who have the least straight-line speed on the front row, and then it’s us and then the Ferraris are obviously almost 10kph up on everyone else.

“I try to visualise how that could like down the straight [opens arms out wide] and through the first corner, I just hope we come out of it with two cars intact.

“We have it in our hands in that having a good result with Lewis tomorrow, that could be the decisive result for his championship, but it is not done yet,” he added.

“We mustn’t drop the ball. It’s about carrying the ball over the line.”

Hamilton made reference to his incident with Vettel at the start of last year’s race when asked if he could consider a cautious approach considering the title permutations heading into the race.

Bottas reckons opportunities will present themselves due to the powerful effects of the tow on the long run to Turn 1, though he acknowledges he cannot afford to risk everything given Mercedes’ situation in the championship fight.

“It’s a long run into Turn 1, a bit like Sochi and the tow has a big effect,” he explained. “Obviously we haven’t been the quickest ones on the straight lines here, but the tow effect is certainly going to help.

“A lot tends to happen here in Turns 1, 2 and 3, as we saw last year with Lewis and Sebastian. So you never know.

“I have nothing to lose in the championship, but I have to keep reminding myself that we’re still fighting for the constructors’ championship - so I have to measure the risks. I’ll try to go for any position I can gain.”

Asked how he will approach the start, Vettel replied: "It depends on the start. We start on the dirty side, and I don't know how much of a disadvantage it is, but it is a long way to Turn 1.

"Usually the problem is you have no place to go. We'll see how other people's starts are, and how ours is relatively, and then we see what happens.