Simon McKeever of Irish Exporters said he was frustrated: “The impact is affecting Ireland and the UK, and indeed Wales.

“From an Irish point of view it’s impacting manufacturing business because they’re waiting for critical inputs, the raw materials to turn it and send it back off the island.”

He said delays would also hit consumers, with the trailers stuck in Holyhead and Dublin containing “a bit of everything” from pharmaceuticals to foods.

“If it reopens [on Friday], my logistics members are telling me we will have a great Christmas,” he said.

“If it’s not, and this goes into next week, and it goes into the additional amounts of passenger volumes that will be on with their vehicles on those vessels, then we’re going to have a problem.”

Mr McKeever said the Welsh government had been “extremely helpful” this week, but said both Welsh and Irish government would need to intervene if there are further delays reopening the port.

“I know they are active in this as well,” he said, adding that “there’s a higher level of coordination that will be required if the port doesn’t open” on Friday afternoon.