Northern Ireland's First Minister Peter Robinson has described the increase in cross border shopping as the latest example of swings and roundabouts. He pointed out that there were occasions in the past when it worked in the other direction.

Many Northern businesses are benefitting from the large increase in customers from the Republic.

Even before sterling weakened against the euro, traders in Northern Ireland towns like Newry, Enniskillen and Derry were reckoning that 40% of their turnover was coming from Republic of Ireland shoppers.

But the current situation has led to traders and politicians in the Republic calling on shoppers to be patriotic and shop at home.

'There have been many occasions when it has workled in the other direction', said Northern Ireland's First Minister Peter Robinson.

'It worked in terms of fuel aggregates when very clearly it damaged the prospects of businesses on our side of the border. I encourage people to come to Northern Ireland and am delighted that they built all those good roads so that people could come up quickly to Northern ireland,' he added.

'We all know that human nature clearly tells us that over the course of many years people in the border areas and indeed people wider afield will travel almost anywhere to get a good bargain', commented the deputy first minister Sinn Fein's Martin McGuinness.