You have to get up very early in the morning to catch Dublin Port’s customs officials on their latest Brexit drive.

The first fingers of dawn are barely visible on the eastern horizon when yellow-vested customs officers arrived at Dublin Port at 5am in time for the first ferry sailings into the port.

Their mission, which started last Friday, is to give customs advice to truck drivers in advance of Brexit and to hand out leaflets. It is a beautiful morning, with hardly a breath of wind, the calm before the storm, a little like Brexit itself.

There is an air of unreality about events. A no-deal Brexit, which will transform activity at the port and make life for hauliers a lot more complicated, is due on Friday unless politicians reach agreement or something turns up like the character out of Dickens.

The leaflet outlines what truck drivers must do in the event of a no-deal Brexit. Unless an agreement is reached at 11pm on Friday, Britain will become a third country as far as customs declarations are concerned.

Companies will have to make a customs declaration if they are trading with the UK. It will be made via an entry summary declaration (ESD) for which truck drivers will be given a master reference number (MRN). This will determine whether they will be in the green lane which means they can exit the port without stopping or in the red channel where they risk being detained by customs officials.

Strictly speaking it is not the responsibility of truck drivers to ensure that the goods they are carrying are customs compliant. That is the responsibility of the company which is transporting the goods, but they will be the ones at the cutting edge of any delays.

The head of Revenue’s Brexit policy unit, Lynda Slattery says they have already targeted others “further up the food chain” in a series of seminars since Christmas.

Nevertheless, even with Brexit looming, only half of the 84,000 business in Ireland that trade with the UK have registered for customs declarations.

“The big issue is how prepared are businesses,” she states. “The State will be able to respond from Friday. The feedback from our seminars is that businesses are not sure if Brexit will happen or not.”

Her warning to wavering businesses is blunt. They must prepare for an imminent hard Brexit.

“Is your business going to survive after 11pm on Friday night if you haven’t done anything? That’s a genuine question for businesses.”

Rita O’Hanlon, one of the customs officials handing out fliers, said many of the lorry drivers they had spoken to had not received any information about the matter before being approached by them.

She said the views of cross-channel lorry drivers ranged from “absolute fear to total ambivalence – some of them don’t believe Brexit will go ahead and others say they haven’t a clue about what is happening. Some have an abject fear of being delayed for hours in the port.”

One truck driver, who didn’t want to be named, cheerily predicted that Brexit “won’t happen. It will dwindle out and the next thing there will be nothing.”

Ryan Harlow, a driver for Agromerchants in Lisburn, carries loads between Warrington and Dublin Port and Holyhead. He is not so optimistic.

“I live in Donegal and I drive a Northern reg truck [to] England. It doesn’t get any more complicated than that,” he says.

“I could lose my run because of it. I’m on a set run. I have a half an hour to get to Ashbourne, tip a truck and get back into Dublin Port and I will have to clear customs twice.”

Chris Stewart from Stewart International, haulage company based in the North predicted that hauliers from Northern Ireland will stop using ports in the Republic if a no-deal Brexit comes to pass.

“Everybody from the UK is going to use UK boats rather than going through the South. It will hurt shipping in the South,” he said.