The creation of a ‘border down the Irish Sea’ and customs checks between ports in Wales and Ireland would have a “devastating impact” on the economy of Anglesey.

That is the view of Anglesey Council’s economic chief ahead of today’s crunch Commons vote on the Prime Minister’s new Brexit plan.

The deal, unveiled earlier this week, agreed between UK and EU negotiators, proposes  a “border in the Irish Sea”, in order to avoid a physical border on the island of Ireland.

Holyhead is the UK’s second busiest port, with 400,000 lorries and trailers and half a million cars passing through every year.

But despite operators previously expressing concerns over the physical capacity to accommodate this necessary additional infrastructure, many Brexiteers feel that the swift movement of goods is so important that such ports will find a way to get around the challenges.

While the proposals would not affect individual travellers, any hauliers taking goods across the sea would have to let inspectors check their lorries to ensure their loads comply with EU rules.

They may also have to fill out customs declarations, but the Government says that these checks may take place at factories and warehouses, rather than at ports, to avoid delays at key infrastructure points such as Holyhead.

But Cllr Carwyn Jones, who holds Anglesey Council’s economic development brief, said: “This deal sounds like a terrible one for Holyhead and Anglesey.

“Its a case of jumping from the frying pan into the fire, and in effect the hard border will be in Holyhead.

“To deal with that we need all sorts of controls and the infrastructure and personnel aren’t here, it could have a devastating impact.

“We are worried about the potential delays and congestion as a result and we fear that Wales will be bypassed completely and that the Rosslare to Cherbourg will be used more extensively.”

Meanwhile the island’s MP has confirmed he intends to vote against Boris Johnson’s deal, claiming it is “even worse” than Theresa May’s deal which the commons rejected on three separate occasions.

Albert Owen added that it was a “bad deal for jobs and trade for Anglesey, Welsh, English and Scottish port communities.”

But Welsh Secretary Alun Cairns said that the deal provided certainty for businesses, urging  all MPs to “get behind this deal” “so that we can focus on building on the UK government’s plans for an ambitious Wales as part of a strong United Kingdom”.