Speaking as the UK government publishes policy papers outlining its negotiating positions on Brexit, Congress Assistant General Secretary Owen Reidy said that "a North-South or an East-West border would be unacceptable on the island of Ireland."
Mr Reidy stated: 'these papers highlight the fact that even at their very best any future arrangements post Brexit may be less favourable than the current situation. At worst the proposals outlined by the British government are completely unrealistic.
'the issue of customs arrangements between the UK and the EU and the border between the Republic and Northern Ireland are inextricably linked.
"Clearly any type of border east/west within the UK is unacceptable and creates problems for unionism. Equally any hard border north/south is also unacceptable as it creates problems for nationalism. Therefore, the Irish government must use its strategic influence on this matter to ensure that the EU and the UK seek neither option," Mr Reidy explained.
"What Britain, the Republic of Ireland, Northern Ireland and the rest of the EU need is the softest possible Brexit (if Brexit has to occur). The people and economies of the Republic of Ireland, Northern Ireland and Britain must not be punished though any Brexit agreement. If it is to survive and prosper the EU requires volunteers not conscripts.
"We propose that, in the event of the UK deciding it must leave both the single market and customs union that a free trade agreement be done between the EU and the UK. But in conjunction with this the UK should agrees to apply the CET (Common External Tariff) in its trade deals with third countries for an agreed period of time.
'such an arrangement would provide stability and balance required by all. We must ensure that workers in Dublin, Belfast, Birmingham and the rest of the EU do not pay the price of Brexit," My Reidy concluded.
A copy of the Congress paper on Brexit is available here