The head of Retail Excellence has said the Government needs to re-open click and collect services, to avoid a surge of shoppers crossing the Irish border.
The retail group said it was disappointed at last week's decision not to allow click and collect services to resume this month.
The resumption of the service is currently set for May 4th, "subject to prevailing public health situation".
Duncan Graham is managing director of Retail Excellence, and said that needs to happen sooner.
He told Newstalk Breakfast concerns over a new wave of cross-border shopping is "undoubtedly" a worry for his members, as Northern Ireland is set to open up retail before the Republic.
"All of this is done with the Government saying they don't want to see this movement of people in the economy at the moment - and yet that opening of Northern Ireland is only going to make things more difficult.
"At the very least we need to be looking at the opening of click and collect around the same time that Northern Ireland goes live".
He said they were hoping for more under the Government's latest plans.
"This was certainly something that we were looking for - we were really disappointed.
"I think there was an expectation from some of the things that the Government had been saying, certainly through March, that click and collect might be the first thing that would give.
"So we're left with a situation where the announcement that was made on Tuesday night was really kicking the can down the road yet again until May.
"And even if you look at the Government's website, it's saying it will be May subject to the prevailing health situation.
"So again, we're left wondering whether it actually will be May".
'You can travel but can't buy a book'
Mr Graham said it makes no sense, as people will be able to travel again from next week.
"You will be very shortly able to travel across your county, you'll be able to visit the zoo from mid-April, but you can't pick something up from a local shop.
"You can go and get a coffee and a takeaway meal, but you can't pick up a book.
"It's really difficult to fathom why this hasn't been re-introduced now at this stage".
On essential versus non-essential retail, he said people are now making up their own minds.
"I think the consumers are now at a point where they're almost deciding what they believe is essential and what's non-essential.
"This has been going on now since the 31st of December - and to a certain extent you can understand people get it for that first few weeks, and they understand they can do without clothes for a week or a month or so.
"But to have been going on this long, those lines do get blurred.
"We saw it happening in the week, with the Government backtracking and announcing that children's footwear was going to be essential".
'The only way they can trade'
And he said there is a misconception that all retail is now online.
"I've been talking to various Government ministers over the last month or so, and one of the things they will say is 'We've been astounded by the amount of interest there's been on the online grants'.
"And of course there has - most retailers are seeing that as really one of the only ways that they could trade.
"But if you talk to most retailers, they will say to you that it's a drop in the ocean.
"If you look at the amount of money that they're taking online, it represents about 20% of the business that they were doing in 2019.
"And of course not everybody's been able to do that".