Japanese carmaker Honda has warned that production at its Swindon plant will be disrupted, after transport problems caused a shortage of parts.
The plant operates on a "just in time" production system, where parts arrive at the factory when they are needed.
Honda has told employees that it is currently experiencing vessel delays and congestion at UK ports.
It will pause production on Wednesday "due to transport-related parts delay", the car giant said.
"The situation is currently being monitored with a view to restart production as soon as possible," Honda said.
It is looking at other arrangements such as air freight.
Congestion at UK container ports has been building up in recent weeks, causing problems initially at Felixstowe, but recently at Southampton and London Gateway as well.
The backlog has built up as companies increased orders after the initial pandemic lockdown, while some have looked to stockpile goods before the end of the Brexit transition period.
Problems at the UK's container ports have been building up for weeks. Businesses have been complaining about consignments being delayed, or even ending up on the wrong side of the channel. Now a major manufacturer has admitted production will be disrupted.
So what's gone wrong? Issues at Felixstowe, Britain's biggest container port have been evident for some time - blamed by hauliers on a vehicle booking system that they claimed simply didn't work, preventing them getting into the port.
The Covid outbreak has also caused problems - which were exacerbated when thousands of containers of PPE imported on behalf of the government were simply left within the port for weeks, adding to the gridlock. And after the lockdown in the first half of the year, the volume of goods being imported has been much higher than normal.
Congestion at Felixstowe has pushed more container traffic to Southampton and London Gateway - and now the situation in both of those ports is also reportedly getting worse.
Honda is looking at air freight to ease its supply problems. The chances are other businesses may have to do the same.
Congestion at England's ports is now so bad that some shipping firms have limited the amount of cargo they will bring to the UK.
Consignments have reportedly been offloaded at continental ports such as Antwerp, Rotterdam and Zeebrugge.
In a statement, Honda said: "Honda of the UK Manufacturing has confirmed to employees that production will not run on Wednesday 9 December due to transport-related parts delays."