The scale of the practical challenge facing the island in the event of a ’hard-Brexit’ was outlined to a Tynwald committee.

Charles Coué, collector of Customs and Excise, was giving evidence to the constitutional, legal affairs and justice committee.

Under the 1979 Customs and Excise agreement, the Isle of Man and UK are treated as a single VAT area with goods moving between the two treated neither as imports or exports.

Outlining his work in scenario planning ahead of the UK withdrawing from Europe, Mr Coué said one practical area of work involved looking at how parcels, freight and passengers are handled over the potential new borders.

He added: ’We also have to consider the resource and infrastructure implications of a hard-Brexit such as the manning of physical border checks and the facilities at our ports to be able to effect those checks.’

There is also the post to control, he explained, with his team having to raise and collect Customs and VAT import duties on package and parcels arriving in through the post.

With online cross-border shopping year-on-year we continue to see increases in the volume of goods arriving through the post, he said.

He said Customs and Excise’s role is to police our external borders to ensure goods entering the Isle of Man, and so the UK, from third countries meet any rules governing their importation and that import taxes are properly accounted for and calculated.

He said his team currently handle around 180,000 packages a year. But post-Brexit, checks at the Post Office sorting office will have to be expanded and manpower increased.

Every item has to be x-rayed and those coming from a third country should carry a Customs declaration.

With the advent of Brexit there will be a lot more countries from where charges will now have to be raised on post. Secure facilities will be needed at the sorting office to hold onto a considerable number of packages at any one time until the correct duty has been paid.

Committee member Lawrie Hooper said the evidence in the UK was that there would be a five-fold increase in activity. Mr Coué agreed the increase would be similar here.

’There’s the potential for a lot more traffic coming in and potentially we could be looking at policing the border not only for traffic from Dublin but also from Belfast,’ he said.

He said there had been preliminary discussions about additional staffing but this was difficult to put in place without knowing what the outcome of Brexit discussions will be.

’But I envisage that if we have a hard Brexit and we have to police both ports, and the increasing post, we would be looking at in the order of 10 to 15 additional staff,’ he said.

Mr Coué said the island was totally reliant on the UK making the changes to its electronic tariff systems.

Asked whether Brexit offered potential opportunities to the island, he said that the UK at the moment is saying its chosen path is to retain a VAT system similar to the EU. There may be the opportunity to tweak the rules that may advantage us, but not over the UK, he said.