The current arrangements on the Border between the Republic and Northern Ireland will not survive if the United Kingdom leaves the European Union, according to Ireland's EU Commissioner Phil Hogan.

Addressing the Oireachtas EU Affairs committee today, the Agriculture Commissioner spelled out the potential consequences of Brexit for Ireland.

“We must get used to the salient facts: in the words of President [Donald] Tusk last week, echoing those of President [Jean-Claude] Juncker the week before - the United Kingdom’s choice is between ‘hard Brexit’ and ‘no Brexit’.

“And, it’s only ‘no Brexit’ that can give us the Border we have now,” he told the committee.

Mr Hogan spelled out his belief that the consequences of Brexit for the UK would be extremely damaging.

“What is clear above all, is that any deal, by its nature, will be inferior to the deal that the UK currently enjoys due to its membership of the EU. The UK is going to learn a hard lesson - it’s not going to have its cake and eat it.

‘Fancy talk’

“The posturing and fancy talk of Brexit is already beginning to collide with reality,” he said.

The Commissioner said that since British prime minister Theresa May had announced she will give formal notice of the UK's decision to leave by the end of March, things had begun to clarify.

"The pound has weakened. We also have a sign of how Brexit will raise food prices in the UK - with the Marmite spat between Unilever and Tesco, Unilever wanting to put up prices, Tesco resisting - at least for a time."

On the question of the Irish Border, he said it had been purely an Ireland-UK affair until 1973, when it had become an EU affair.

“Now, for the first time in history, its trade or economic aspect is about to become an EU-UK affair, or an EU-Ireland-UK affair. Just think how important the EU aspect will become if the UK turns again to a cheap food policy as part of its drive to become more competitive in international markets.

“North of the Border will be cheap food and a different way of supporting farm incomes, whilst South of the Border will be the Common Agricultural Policy,” he said.

It was obvious, he continued, that Brexit concerned Ireland almost as much as the UK, and he predicted that conversations between Dublin and Brussels would be almost as significant as those between London and Brussels.

Mr Hogan said the extent of economic integration on the island of Ireland was unmatched anywhere else in the EU, and thus the level of potential disruption from a so-called “hard Brexit” would be considerable - and that had been acknowledged in last week’s budget.

Northern Irish milk

He pointed out that 40 per cent of all Northern Irish milk is processed in the South; more than 50 per cent of Irish beef and cheese go to the United Kingdom; 40 per cent of Ireland’s exports go to the UK, while Ireland’s all-island energy market, cross-Border healthcare, fisheries and aviation would all be potentially affected by a hard Brexit.

“On the other hand, a hard Brexit might provide new opportunities for Ireland. For example, what will happen to Britain’s financial services sector if it loses its all-important passporting provision - will inward investment choose Ireland rather than the UK?”

He said that while these possibilities did not, for the moment, seem to offer a consolation for the difficulties Ireland was already experiencing due to the decline of Sterling, they raise unanswered questions.

He said there were other delicate political issues, not least of which was the status of the Belfast Agreement, which was underpinned by reference to EU law.

“And then there is the future of the Common Travel Area and the status of Irish citizens in the UK - something of concern given the present weight of opinion against EU citizens working there - and British citizens resident in Ireland, of which there are over 250,000.”

Mr Hogan pointed out that Britain traded more with Ireland than it did with China, Japan, Russia and Brazil combined.

He said the Brexiters in Britain argued that strong industrial interests in France and Germany will lean on their governments to conclude a quick deal with the UK.

“We shall see. All I would observe in this connection is that the referendum discussion was characterised by half-truths and some outright lies. We already see some features of Brexit becoming evident - even though they were dismissed in the referendum debates as scare-mongering.”