A no-deal Brexit could result in skyrocketing sandwich prices, a renowned family baker has warned.
Of the three flour mills on the island of Ireland, just two can supply industrial qualities and are both based in the north.
This means we currently imports tonnes of flour from Northern Ireland and Britain.
If the UK crash out of the EU without a deal, flour could be subject to a tariff of €172 a tonne, affecting the prices charged by commercial flour suppliers in Belfast.
Family business Cully's Bakery in Co Cavan fear they will be hit hard by high duty prices.
Brían Cully, director of the business told RTE: "Flour for us is huge, there could be a duty of 25-26%. In that case it will drive the cost of bread up for everyone in the country".
Bakers do have the option of importing their flour from other European countries but it will cost more to get to Ireland.
"A sandwich could double in price overnight so it really does affect everyone," Brían cautioned.
Brían is also concerned about the possibility of a hard border as Cully's supply their bread to shops in Keady, Middletown and Armagh City as well as to the border counties of Monaghan, Cavan, Leitrim and Longford.
He said: "We go to the North as part of our run, getting through the border will be a problem if there's customs checks and then there's customs declarations.
"They'll have to be made long before you move any of your goods so that will cause us issues".
