The Government Chief Whip says Irish retailers will suffer if shoppers choose to go to Northern Ireland to do their Christmas shopping.
A Red C poll in the Sunday Business Post shows that one third of people are planning a shopping trip to the North in the lead up to the festive period, with 56% of cases of those living in border counties.
Since the Brexit vote, Sterling has taken a slump and consumers are cashing in on the weak exchange rate to Euro.
Fine Gael TD Regina Doherty, says although consumers may benefit in the short-term, the decreasing value of Sterling is bad news for retailers south of the border.
"This is a very real impact", she said. "To normal people, they'll see it as a positive, but in actual fact it's going to be a real negative to our retail industry."
The surge is also reflected in online sales, with 29% of people polled saying they had been purchasing more goods online from British sites since the Brexit referendum.
Sterling is currently at a four-year low, trading at about 90 pence last week.
The North's First Minister Arlene Foster the Democratic Unionist Party (DUP) this week that the Irish position on Brexit was being fuelled by political instability.
She said: "Now, I am pleased that relations with the Irish government are probably as good as they have been at any point in our history and I will continue to work with them where it is in the best interests of Northern Ireland to do so.
"However, the reality is that political instability in Dublin, and fears of their own future, are driving their decision-making at present as much as any concern about Northern Ireland.
"And while they seek to take the views of people of Northern Ireland on the issue of Brexit at home, their representatives are sent around the world to talk down our economy and to attempt to poach our investors."
