Niki Lauda thinks Mercedes needs Sebastian Vettel to retire “at least once” in the remaining 14 races of 2017 to stop the Ferrari driver running away with the championship.

Vettel led a Ferrari one-two in Monaco as both Mercedes drivers finished off the podium, extending his lead over Lewis Hamilton to 25 points — exactly one race win’s worth — and the team’s to 17. Monaco’s result led to Mercedes boss Toto Wolff to label his team the underdog after three years of dominance.

Much of the team’s struggles in Monaco were down to a failure to extract the most out of Pirelli’s softest tyre (the ultra-soft), which will be used again at the next race in Canada. Lauda, the team’s non-executive chairman, thinks the world champions are in danger of losing touch with Ferrari.

“We need to find a solution for the tyre window,” Lauda told Kronen Zeitung. “And one thing is clear: Vettel needs to retire at least once, otherwise it’s all over. Ferrari has got momentum going. If it stays like this the gap will become huge … alarming.”

Hamilton has admitted confusion at the tyre issues he encountered in Monaco, where he was eliminated in Q2 and had to settle for seventh position. The three-time world champion has vowed to look into what caused the problem and has expressed concern he could lose further ground to Vettel in the title fight if a solution is not found.