In the referendum on the UK`s membership of the European Union in June 2016, Northern Ireland voted to remain in the European Union at 55.8% against 44.2%. In a November 2018 opinion poll commissioned by BBC Northern Ireland and RT (Republic of Ireland), 61% of respondents felt that Brexit should not take place if the price was a hard border (compared to 36% that it should, 3% do not know).  If this had been necessary, the backstop would have maintained the whole of the United Kingdom in close trade relations with the EU, which would have excluded the need for controls along the Irish border. Irish Foreign Minister Simon Coveney said that the fact that an agreement in principle had been reached on the outstanding issues relating to the implementation of the Protocol on Ireland and Northern Ireland was good news. Michel Barnier, the EU`s chief negotiator, has announced that he will „find solutions” for the UK and Ireland to deal with threats to Irish trade relations, the common travel area and the Good Friday agreement.  Irish Foreign Minister Simon Coveney denied British media reports that Ireland expected the effective border to become the Irish Sea and said that „British officials were obliged to find an imaginative solution, but [the Irish government] would not support a proposal for a brutal return of the border with Ireland.”  Although the breakthrough of the Irish border issue has been a welcome step forward, negotiators are still stuck when it comes to concluding a trade deal after Brexit before 31 December. Britain and the EU agreed on border issues with Northern Ireland in a breakthrough at the Brexit talks. In October 2019, the UK and EU negotiators agreed on a revised protocol (see below) that resolved many of these problems by allowing Northern Ireland to leave de jure but effectively the border between the islands (Ireland and Britain). LONDON (Reuters) – Britain said on Tuesday it would drop clauses in the domestic bill that violated the Brexit withdrawal agreement after reaching an agreement with the European Union on managing the border between Ireland and Northern Ireland. At the end of September 2019, during the litigation before the courts of the European Union Parliament, Jean-Claude Juncker pointed out that a British animal that theoretically enters northern Ireland could theoretically cross the Republic of Ireland and enter the continental EU from there if there were no border controls.  „This will not happen,” he said, „we must preserve the health and safety of our citizens.”  After Brexit, the border between Northern Ireland and the Republic of Ireland became an external border of the EU.  In theory, a „hard” border could return, both with fewer and monitored border crossing points, to support the necessary customs infrastructure.  Both the EU and UK negotiating teams have made it clear that this result will not be acceptable in any final withdrawal agreement.
 In 1922, the Irish Free State formally separated from the United Kingdom as an autonomous regime under the Anglo-Irish Treaty and was the conditions for full national independence, while Northern Ireland remained a member of the United Kingdom. As a result, the demarcation line between these two parts of the island has become an international border. Cross-border trade in goods and services has been subject to different tax and customs regimes and customs infrastructure has been put in place at designated border crossing points. All traffic was controlled by the jurisdiction in which it entered. This could result in a full search of the vehicle, with delays and inconveniences resulting.