LONDON (AP) — Car maker Honda said Wednesday it has temporarily halted production at its plant in England after shipping delays linked to the COVID-19 pandemic and preparations for Brexit left it with a shortage of parts.

The company was one of many businesses affected by severe congestion at some of the U.K.'s container ports, caused by a combination of international shipping disruptions brought by the pandemic, a surge in imports ahead of Christmas, and companies stockpiling to prepare for uncertainty surrounding Britain's final departure from the European Union single market.

Logistics firms have complained for weeks about bottlenecks at the eastern port of Felixstowe, and retailers have said they couldn't access their goods because containers are stuck on ships unable to unload.

Honda said it was forced to pause production because "transport-related" delays left it short of parts. The factory relies on a "just in time" delivery system, in which parts arrive as they are needed for assembly and not stored locally, increasing efficiency.

"The situation is currently being monitored with a view to restart production as soon as possible," Honda said in a statement.

Tim Morris, chief executive of U.K. Major Ports Group, which represents the nation's container ports, said the pandemic has caused "unprecedented volatility in global supply chains."

His group and other logistics organizations have written to Britain's government, calling for flexible policies to help ease the movements of containers at ports. They said that while the peak of port congestion has passed, "high volumes remain and could persist for some months, running into the period of the end of the EU transition."

"While there are pressures caused by COVID all over the world, no other country is facing the kind of uncertainty we are around the end of the transition period," said Ed Miliband, business spokesman for the opposition Labour party. "With businesses still not knowing whether there is going to be a deal, and the exact nature of any deal, it is throwing massive uncertainty into their decision-making.

The U.K. left the EU on Jan. 31 but remains within the bloc's tariff-free single market and customs union until the end of the year. The two sides haven't yet reached a post-Brexit trade deal, and failure to do so would mean tariffs and other barriers that would hurt both sides.

The Transport Department said officials are working closely with the freight industry to tackle problems in the global shipping system.