Britain is the Republic of Ireland's biggest trade partner in the EU. Ireland's economy depends heavily upon trade with the UK. On June 23rd, Irish people who live in the UK are eligible to vote in the EU membership referendum. The Irish government is hoping that its citizens will vote in support of the remain campaign. Currently, there is no border post between Ireland and Northern Ireland, but that could change dramatically if the UK opts out of the EU.

The UK is Ireland's largest trade partner in the EU—but it's not just trade ties that both countries share. Over half a million Irish citizens are currently living in the UK and are eligible to vote on June the 23rd. Another quarter of a million British people live in Ireland and they too can influence the vote both ways. A common travel area currently exists between Ireland and the UK—allowing people and goods to move freely between both countries. However experts say that if Britain votes to leave the EU this could change.

"I think nobody can be precise yet on what will happen as a lot will depend on what is negotiated between the UK post Brexit and the European Union. But the chances are there will have to be some sort of border because you can't close the front door to continental Europe and leave the back door open through the island of Ireland. Now whether that border however pores it will be whether that's in the island of Ireland between Northern Ireland or between the island of Ireland and Britain will have to be negotiated. But there will have to be a border," Dr. Vincent Power , partner of A&L Goodbody, said.

Deeke runs a diner beside Dublin port. Many of his customers are truck drivers. He says there is a lot of fear about a potential border between Northern Ireland and Ireland if Britain votes to leave.

"It's bound to have some effect on trade here when they re-instate the border in Northern Ireland. It took us 100 years to get rid of the border and now they are putting it back it doesn't seem like the right thing to do. From talking to truck drivers and people like that they are apprehensive that Britain will leave Europe and wouldn't encourage it," Owner of Deeke's Diner Deeke said.

Trade between Ireland and the UK is worth over €1 billion each week. Over 40% of Irish indigenous exports go to the UK and Ireland is the 5th most valuable market for exports from the UK.

"It wouldn't just be exports to the UK and Northern Ireland and imports that would be affected by the reimposition of border. Tariffs would put up the cost of exports and a potential border could slow things down. But think of all the manufactured goods that go from Ireland through the United Kingdom into continental Europe so that whole chain could be slowed down," Irish Exporters Association CEO Simon Mckeever said.

If Britain was to leave the EU, Ireland may benefit by attracting additional foreign direct investment. However many here say that the negative impacts on trade outweigh this.
The Irish government and many Irish business groups are backing the remain campaign and have called on people here to phone a friend in the UK and ask them to use their vote to ensure the UK remains in the EU.

If Britain votes to leave the UK, this will have profound impact on trade between Ireland and the UK. Not only is there a possibility that tariffs on goods going between both countries will be re-introduced but a physical border between Northern Ireland and the Republic is likely to be re-constructed yet the shape of what this will look like is still unknown.