MONTMELO, Spain -- Mercedes boss Toto Wolff fears Brexit will be "the mother of all messes" and hurt the seven Formula One teams based in the U.K., strengthening Ferrari in the process.
Britain is due to leave the European Union on March 29, although its parliament is yet to agree to the terms of its departure. It remains a possibility it could leave without key deals around trade and immigration in place.
The reigning world champions employ over 1,000 people across two factories in the U.K., which has traditionally been where the majority of F1 teams are based. Wolff is worried about how the industry will change in that scenario.
"Yes, Brexit is a major concern for us and should be a major concern for all of us that live in the U.K. and operate out of the U.K.," Wolff said during the opening day of preseason testing on the outskirts of Barcelona. "We're Formula One teams that travel to tests and travel to races at least 21 times a year.
"We are moving in out of the U.K., our people move in and out of the U.K, the way we are getting parts and services at the last moment into the UK and any major disruption with borders or taxes would damage the F1 industry in the UK.
"Our team is an international team, a German brand, that has its F1 operations in the United Kingdom, and I think we will have around 15-20 different nationalities in our team and many EU citizens and uncertainty at the moment at whether the industry will be impacted by a no-deal Brexit or a Brexit.
"That is damaging to what is to me one of the outstanding industries in the U.K.. We have said before that it is the mother of all messes."
He added: "We are looking through the various scenarios with Mercedes Benz U.K. because it not only impacts Formula One, it also affects the mother brand in terms of getting cars and parts in and out of the country.
"If a no-deal Brexit would happen like it is being discussed, I think it would have a major impact in terms of our operation in terms of going to the races and getting our car developed and ready. That is a nightmare scenario that I don't want to envisage."
When asked if he felt the upheaval likely to come with Brexit would hand an advantage to Ferrari, he said: "Well, everybody at Ferrari and also Sauber [now Alfa Romeo] in Switzerland will have a massive advantage over every UK-based team."
Wolff says he and David Richards, the head of the governing body for British motorsports, have discussed writing a letter to the U.K. government to make their concerns clear.
"David and I discussed it over the Christmas and holiday period as to whether we should actually write a letter and get involved, and he felt, as the head of British motorsport, we need to do something because the industry is at risk.
"We have fantastic access to talent today in the U.K. ,and F1 has grown to what the Silicon Valley is in the U.S. At the moment there is a risk of whether the UK can stay as competitive a location as it is today. We would very much hope that it stays like this."
Red Bull, McLaren, Williams, Racing Point, Haas and Renault are the other teams based in the U.K. Red Bull boss Christian Horner sounded less alarmed on the topic when pressed on it at his own Monday media session.
When told Wolff's comments, he said: "You can paint a doomsday scenario or you can maybe say, 'how much is it actually going to affect our daily life?' I don't think any of us can actually answer that question.
"So until a solution is found and a deal is put on the table, then we know what we're dealing with, then we can adapt. When you're swimming in the fog at the moment, it's very difficult to make plans without clarity.
"How many of you understand what Brexit is? Brexit is something that consumes the news, every time you turn the television on at the moment, you've got someone talking about a hard Brexit, a soft Brexit, a backstop, whatever it is. Obviously as a team we do our due diligence. But whether there's a no deal, any deal ... we will have to deal with it. Ultimately life will go on. It's important that we get to a conclusion sooner rather than later because it's unsettling for so many aspects.
"Brexit is something that really does need to be addressed for the clarity, for everybody, sooner rather than later."