Manufacturer deals ‘difficult’ in Formula 1

Williams, a team with the fifth biggest budget, punched above its weight for the second successive season in 2015, finishing third in the constructors' championship.

The team parted ways with works partner BMW at the end of 2005, after the relationship broke down when BMW criticised the team for not being able to produce a car capable of winning the constructors' championship and Williams blamed BMW for a lack of power.

Over the next eight years, Williams struggled and managed just one win and three other podiums.

But after securing a long-term engine supply deal with Mercedes, signing big name sponsors and recruiting key people like technical chief Pat Symonds, the team turned its form around.

"I really value the independence that we have, it's really important to me," deputy team principal Williams told Autosport.

"No one can deny having the backing of a manufacturer financially is critical.

"But unless we have a good relationship and understanding and respect of each other's strengths, weaknesses and boundaries, it would be very difficult to make it work, particularly in a culture like our team.

"I like the structure that we have at the moment, but that's not to say that I wouldn't appreciate if a manufacturer were to look at us and say 'we'd like to partner with you'.

"If those terms were appropriate and worked for both parties then it would springboard us into another sphere.

"But currently - yes we're only a customer team but we have a great relationship with Mercedes.

"We work very hard on that relationship to make sure that we've cultivated this partnership, it's as strong as it can be, and we have a long-term relationship with them.

"So at the moment we're very happy with that and I like the way things are working."

Williams is adamant the team can challenge for the title, even without financial backing from a manufacturer.

"Some people have been saying we could never win but look what happened in Silverstone," she said.

"We overtook them [Mercedes] and we led for 20 laps, and it was only really because our car wasn't strong enough to keep them behind us, that wasn't the power unit it was the car.

"We have to do a better job on the chassis side and then we can fight for wins and we can fight Mercedes for a championship.

"This is not all about engines in Formula 1 as much as what the paddock says.

"If we do a better job chassis-wise then of course we can take the fight to them and I 100 per cent believe that."