Ford Motor Co told British Prime Minister Theresa May that it is stepping up preparations to move production out of Britain, The Times reported on Tuesday.
The automaker told the prime minister during a private call with business leaders that it is preparing alternative sites abroad, The Times said.
Ford was not immediately available for comment.
Ford, which operates two engine plants in Britain, last month said that it faces a bill of up to $1 billion if Britain leaves the Europe Union without a deal.
Automakers and other manufacturers have warned about the toll a no-deal Brexit could impose, including higher tariffs, disruption to supply chains and threats to jobs. Britain is scheduled to leave the European Union on March 29.
Another participant on the private call with May said that other companies delivered the same warning as Ford, The Times reported.
"This isn't about contingencies any more - we are taking steps because of the uncertainty. It's real," the participant said during the call.
Last week Nissan Motor Co. said it scrapped plans to build the new X-Trail SUV in Britain and will produce it solely in Japan, saying that uncertainty over Britain's departure from the EU was making it hard for it to plan for the future. Ford is the top-selling automotive brand in Britain, which is its third-largest market and the destination for roughly one in three cars made at its plant in Cologne, Germany. It employs about 13,000 people in Britain.