Theresa May's speech of January 17 has been justifiably described as somewhere between catastrophic and disastrous in its implications for the island of Ireland.

The threat to leave not only the single market but the EU's customs union as well will clearly have hugely damaging consequences for trade in both directions between Britain and Ireland. It will also make the creation of a hard border between the North and the Republic almost inevitable.

It is curious, therefore, that the speech seems to have been welcomed here by some at the highest levels of Government. Presumably, they were seduced by Mrs May's honeyed words referring to the special relationship which exists between the UK and the Republic and her desire to maintain the Common Travel Area (CTA) between our two countries. In my view, however, the CTA is a poisoned chalice that currently offers very few benefits to Ireland.

The CTA is essentially a mechanism which enables the UK to control immigration into Ireland. In other words, Irish immigration authorities have to ensure that all non-nationals requiring visas to enter Ireland from outside the CTA are pre-approved by the British Home Office.

In my own experience serving in Irish embassies abroad, there have often been interminable delays while I waited for such pre-approvals to be granted for visa applicants wishing to holiday or study in Ireland - who under any other circumstances could only be described as highly desirable visitors. One could not help but suspect that requests for visa clearances emanating from our Department of Justice did not rank highly in the Home Office's list of priorities. Needless to say, consultation did not take place in the opposite direction.

It is argued, of course, that the CTA greatly facilitates travel between the Republic and UK. But is this really the case? We all know that air travel from here to the UK already requires a valid passport or other photo identification. Would there be any great change in practice if the CTA ceased to exist?

The Border

The crux of the whole matter undoubtedly is the Border with Northern Ireland. No amount of deft diplomacy will prevent the creation of a hard border between the North and the Republic if Mrs May (pictured inset) makes good on her threats regarding the single market and the customs union.

So it is essential that the Irish Government focuses its efforts on protecting the terms of the Good Friday Agreement in full and seeking to uphold the will of the Northern Irish electorate as expressed in last June's referendum. In this regard, a special status arrangement with the EU for Northern Ireland seems to me to be essential.

Failure to achieve this will create a vista almost too grim to contemplate.

How this special status can be obtained is clearly a matter for lengthy negotiations with both London and Brussels in the coming months and years. Whatever the eventual outcome, achieving such an arrangement should be the Irish Government's prime objective.

Without every possible pressure being exerted by Dublin, it seems certain that few concessions will be granted by London to recognise the North's unique requirements. Nor can much help be expected in this regard from what is likely to be an increasingly dysfunctional Belfast Executive.

British Objectives

Having said all that, I believe that those who doubt the sincerity of Mrs May's commitment to friendship with Ireland are probably mistaken. She does indeed want a close relationship with the Republic - but it will not be one based on the principles of equality or evenhandedness.

Instead, she would seem to envisage a return to the old days prior to EU membership, when the Republic was often little more than a client state of the UK. Under such circumstances, there would be no difficulty for London in agreeing to the greatest possible freedom for the movement of people and goods between and within our two islands. Indeed, if we Irish were eventually to detach ourselves partially or completely from the EU, that would be even better from a British point of view.

That, however, is not what the vast majority of Irish people want. By allowing ourselves to be persuaded that retention of the CTA is a major policy objective for us, we would not only become unpaid agents for the protection of Britain's borders but we would also risk losing much of the hard-won sovereignty which our EU membership has enhanced. The CTA should be regarded as little more than fool's gold which will prove worthless unless we grasp the bigger picture.

In this respect, our long-delayed membership of the Schengen Agreement may well prove much more beneficial to us than retention of the CTA.

Overall, Mrs May's speech was patronising to all Britain's EU partners - but particularly to us. She stated at one point that she alone would act on behalf of "all four nations of the UK", including, presumably, the Irish nation.

She failed to recognise that of the 6.5 million members of the Irish nation currently resident on the island of Ireland, fewer than two million come under her jurisdiction - and even of these at least 56pc have no desire to leave the EU at all.

Unless Mrs May takes lessons soon in geography as well as history, it may prove very difficult for us all to avoid the chaos which Brexit is likely to unleash upon these islands.

Dr Niall Holohan retired as Ambassador to Saudi Arabia after 40 years in the Department of Foreign Affairs and Trade. He has also served in the Secretariats in Belfast and Armagh

Irish Independent