Non-essential retail outlets will close from midnight on Wednesday when Ireland goes into a second lockdown due to the coronavirus pandemic.
But they will remain open in Northern Ireland, which has caused concern for business owners in border areas.
Martin Travers, the owner of Petals Flowers in the Clanbrassil Centre, Dundalk, said he found the situation “hard to grasp.”
He said: “The restrictions and that is very hard on us.
“I can’t understand how the retail in the North is allowed to open and their infection rate is the same as up here.
“The population is far lower in the North and the retail is allowed to open in Northern Ireland.
“And they’ll be able to still travel from Northern Ireland into the Republic.”
Asked about the impact of the new restrictions on his business, Mr Travers replied: “It will just flatten it to the floor.”
Mr Travers started his business 26 years ago and runs the shop by himself.
He said: “There were tough times then too, but we’ve never seen anything as tough as this.
“It’s just hard to grasp that the retail in the North is allowed to open and we have to close in the Republic.”
He added: “It’s hard to know what to do.
“I just hope that the infection rate will drop when the restrictions come in and that we’ll get back open for Christmas.
“That’s all we can really do.
“It might change but nobody knows with the infection, how it will spread.
“We still mightn’t get it open for Christmas.
“With any business, we just hope that the vaccine will come quickly and we’ll be able to get back to normal.”