Mercedes has played down any suggestion of foul play from Ferrari to obtain their current engine advantage.

Last year saw a lot of speculation surrounding the Italian team's power unit and in particular their ERS due to an innovative split battery design which led to questions over whether they were exceeding the allowed amount of electrical power that could be stored.

This season has seen that advantage grow, with Charles Leclerc using it to claim victories in Spa and Monza but Mercedes boss Toto Wolff is comfortable everything is legal.

“We have a pretty good understanding I would say, we have to close the gap," he said of where the advantage lies.

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“Obviously an understanding is a good first step to help them close the gap. It’s a wishy-washy answer.

“We got Monza out of the way and now it is about looking ahead.”

Indeed, after two power circuits, Formula 1 teams face an entirely different challenge this weekend on the twisty streets of Singapore.

And asked if Mercedes were starting to relax and think of 2020, Wolff insisted such a move would be foolish.

“The intensity is still on 2019 as there are seven races to go and we have a solid gap in both championships but obviously a streak of one or two really bad weekends can make it swing in the other direction,” he noted.

“So we have got to keep pushing so that is what we will do. We can’t take anything for granted.

"We knew Spa and Monza would be difficult for us and this is what happened. Singapore on paper looks much better for us and the Red Bulls.

“I have no doubt that Ferrari will have also learned in the meantime and will have a better package there, better than Hungary.”

Despite Marina Bay being considered one of Mercedes' weaker circuits during the hybrid era, they've only lost their once with Sebastian Vettel taking the win in 2015.