The government said it had proposed an ambitious future relationship with the EU to keep trade flowing. Mr Hampton said there was a possibility Stena Line would reduce services to and from the UK as a result of Brexit: "We can't plan on the basis of what we don't know, so we're very anxious about the outcome," he told the BBC's Today Programme.
Hampton warned traders could stop using Great Britain to get from Ireland and Northern Ireland to the rest of the EU, and instead sail direct to the continent.
A no-deal Brexit that created friction on the Northern Ireland border, or delays if extra checks were put in place between Great Britain and Northern Ireland to implement what's become known as a Brexit backstop, could have a significant impact on trade flows, he said.
Asked if added friction at borders could result in fewer Stena Line sailings to and from UK ports, he said that while the firm did not want to move routes ‘this could be one of the implications’.
He called for clarity from the government about what trade declarations would be necessary in the event of a no-deal Brexit. Without it, he said, delays at ports could affect whether food got to supermarket shelves on time.
Mr Hampton, chief people and communications officer at Stena Line, was also worried about whether a new computer system to handle customs declarations - known as CDS - or its predecessor, could cope with a sharp increase in volumes following a no-deal Brexit.
A government spokesman said it was engaging with ports, and senior officials had visited those owned by Stena Line. "It is crucial to keep trade flowing when we leave the EU," the spokesman said.
