David Richards, the chairman of UK motor racing's governing body, has warned that Mercedes could pull the plug on Formula One if Britain leaves the European Union without a deal.
Mercedes have enjoyed tremendous success in recent seasons and are this year bidding to win their sixth consecutive drivers' and constructors' titles.
Their star driver, Britain's five-time world champion Lewis Hamilton, is entering the first season of his new £40million-a-year contract.
However, Mercedes team principal Toto Wolff has described no-deal Brexit as a "nightmare scenario" which could create the "mother of all messes" for the sport.
Britain is due to leave the EU on March 29. Wolff also indicated that Mercedes might have to consider relocating their F1 operation, which is based in Northamptonshire and employs more than 1,000 staff.
Under the current Concorde Agreement, the world champions are committed to the sport for two further seasons.
And Richards, head of Motorsport UK, raised the possibility that the German car manufacturer may consider their F1 future in the face of a no-deal Brexit.
Richards, who sat down with Wolff during the off-season, told Press Association Sport: "Looking at the investment that Mercedes have in Brackley, and the infrastructure that is already in place there, could a no-deal Brexit precipitate them stopping in Formula One?
"Could it also lead to satellite operations in Europe with some teams moving there? It is a big infrastructure to move, so it won't be straightforward. It's not going to make life for a Formula One team based in England any easier."
Eight of the sport's 10 outfits are situated in the UK and Richards, 66, is startled to hear only Wolff express his concerns.
Richards, who used to run the Benetton and BAR teams, also said that the sport's European season – which kicks off in Spain at the beginning of May – will pose a major challenge under the terms of a no-deal scenario.
"I have been surprised that the teams haven't been overly-concerned about it," he added.
"For some months now, Toto Wolff is the only person that has been very clear on the problems.
"Transport in and out of the country between the European rounds will be a major headache.
"If we get a no-deal Brexit, the early part of the season is going to be very challenging for all the teams, and I don't think some of them have fully considered that yet."
On the second day of running at Barcelona's Circuit de Catalunya, Hamilton was seventh at the lunch break, 1.68 seconds off the pace of Ferrari.
The Italian team were quickest on the opening day, and Sebastian Vettel's new team-mate, Charles Leclerc topped the timesheets for the Scuderia on Tuesday morning.
Williams were absent for a second day having failed to get their new car ready in time.
It remains to be seen when the British team, winners of 16 combined individual and team championships, will hit the track.
After Tuesday's action there are just six days of testing remaining before the teams head to Melbourne for next month's season-opening race.
