Lewis Hamilton and Valtteri Bottas in the ascent but Ferrari expected to dominate in Hungary

Neither of the two Mercedes men believe they are favourites at the Hungaroring this weekend

Valtteri Bottas admitted that he expects the Ferraris to be very fast this weekend (Getty)

Mercedes retook the lead in both the drivers’ and constructors’ world championships at Hockenheim last weekend, courtesy of Lewis Hamilton and Valtteri Bottas scoring a memorable 1-2 on the team’s home ground. On top of that, they confirmed that they have cleared two key players from the driver market by renewing both their contracts.

But neither driver believes that they are the favourites at the Hungaroring this weekend. Hamilton admitted last Sunday evening that the tight track – often called Monaco without the walls – has traditionally not suited Mercedes’ car, and Bottas agreed here on Thursday afternoon.

“It is a maximum downforce track, which means that Red Bull are always strong here, and we expect the Ferraris to be very fast, too.”

This will be a tough weekend for Ferrari, after the sudden death of chairman Sergio Marchionne from a long illness. Such are the exceptional circumstances that both Sebastian Vettel and Kimi Raikkonen have been excused attendance at official FIA conferences, unless they finish in the top three in qualifying or the race.

But though they clearly start as the favourites, a storm is once again brewing over their sheer speed and a recent upgrade said by insiders privy to such matters to be worth 40 horsepower. That is a massive hike by any standard, but representatives of both Mercedes and Renault have been astonished by GPS figures which show the red cars, and those of the Haas and Sauber teams, to have prodigious acceleration.

In Germany last week race director Charlie Whiting met with various parties at Mercedes’ motorhome in the paddock, but later insisted that the FIA are still happy with the legality of Ferrari's hybrid power unit, following an investigation conducted after the race in Monaco into the way it harvests and deploys energy.

"Some teams have been asking further questions and we were just there to try and help them have some peace, if you like," Whiting told reporters.

Sebastian Vettel of Ferrari (XPB Images/Press Association Images)

Mercedes and Renault technicians have suggested they know how Ferrari are getting the extra power, but are currently nonplussed about how to do so themselves without overstepping the regulations. It is believed that the joint meeting was intended to help determine where the technical lines had been drawn.

"We know we have a power deficit, which up until now was against Mercedes," Renault team principal Cyril Abiteboul said. "We see that Ferrari have taken the upper hand, so congratulations to Ferrari in that battle. The step that they have done is amazing. It's a step that they have done to a certain degree that does not go with a hardware introduction, one we see across all three teams, not just Ferrari, but also Haas and Sauber, which are more of a battle for us.

"Clearly we are scratching our heads, because we look in particular at the GPS profile, and we see indeed that it's really strange what they are doing. But doing something strange doesn't mean that it's illegal.”

Elsewhere, the flagging McLaren buoyed their supporters by announcing that they have lured Toro Rosso technical director James Key to fulfil a similar role, after the departure of Tim Goss in June and the resignation last week of Matt Morris.

Key is an old school technical director, who according to his mother drew a plan view and a side view of his first car when he was only two years old.

Ferrari are expected to benefit from a recent engine upgrade (EPA)

“I can’t remember that, obviously!” he admits, “but cars were always something I was interested in and my father was always a car fan. Aged 11 or 12 I was watching TV and there was a Grand Prix on at Brands Hatch and I just got completely hooked. That was just before the Golden Era of Prost and Senna and Mansell. I kind of decided at that time that I wanted to be involved in the sport. It set the path.”

Sponsored by Lotus Engineering through a Bachelor of Engineering degree at Nottingham University, in Mechanical Engineering, his thesis was a data acquisition system for a Jaguar D Type. Presciently, he thought it was going to be relevant for a young engineer wanting to go in the motor racing direction. Later he worked with Lotus Engineering on a Le Mans car project and vehicle dynamics, before joining Eddie Jordan’s F1 team in 1998 as a data engineer with Ralf Schumacher, and later with Heinz-Harald Frenzten in 1999 when they won two races.

From there he expanded his foundation to embrace further critical trackside roles, and did well-received work at Sauber and Force India before joining Toro Rosso. “You need to be able to filter things and learn what’s important and what’s not,” he said. “Doing the trackside stuff first definitely helps you understand that big picture.” His dictum is that while there is much that engineers can learn, a race team is a race team, not a university.

Mercedes know they have a real fight on their hands this weekend (Getty Images)

“F1 is totally different to anything I’ve experienced before,” he said. “You don’t have the long timescales, you don’t have the time to look into things in detail. You have to run a lot on experience to a certain extent, to make a decision. You don’t have that in other industries. If you are faced with a problem in F1, you treat it totally differently. And you’re called to account every fortnight. It’s a very different way of thinking.”

It’s yet to be determined when he can start work and there is likely to be a period of gardening leave, but his signing is a major step forward for a team that have become mired in their complex matrix management system. Adrian Newey may be the last individual overseer of F1 design at Red Bull, but Key has a similar philosophy which could be crucial to a once-great team finding its way back to prominence.

Whether that will be sufficient to keep Fernando Alonso engaged for 2019 remains to be seen – and McLaren have been chasing Daniel Ricciardo as a back-up just in case – but it’s a step in the right direction after a great deal of obfuscation in the last three years.