The price of a can of Coca-Cola could be on the rise if the Internal Markets Bill does not remain barrier free.
he warning came from the drinks giant's new general manager Miles Karemacher, who took up post in February.
He said Coca-Cola, which has 750 staff across its sites here and in the south and produces products at its Lambeg facility, selling around 30% of that produce in Northern Ireland and a further 60% in the south, may have to shoulder additional costs if Brexit is not a seamless process.
Speaking to the Sunday Independent, he said: "We ship a lot of raw material from the south to the north and a lot of finished product comes from the north to the south. In fact, every function is fully integrated. Up until the last couple of weeks we were planning towards some sort of certainty with the Northern Ireland Protocol. That helped us put all the measures in place because we knew what we needed to prepare.
"But then this Internal Markets Bill - we have been very disappointed by that because it creates a lot of uncertainty and it's really difficult to plan against that context in place."
With the Northern Ireland Protocol, there would have been no increase in prices to consumers. Things are less certain now, he says.
"If a World Trade Organisation tariff is applied, that brings a lot of cost to the business and we would need to evaluate what that implication would be to us."
Proposals to change the law to ensure goods can move easily between the UK's four nations after Brexit are currently being debated.
The bill was drawn up to ensure barrier-free trading after the Brexit transition on December 31 but it brings new complications to trading and operations that involve a cross border setup.
There is a possibility that the bill could contradict previous agreements. Coca-Cola is not the only food and beverage firm operating within the two jurisdictions. Companies like Diageo, which produces Baileys and Guinness, and some agri food firms also benefit from the frictionless movement between north and south.
In a report in 2017, Diageo, which is made at the St James's Gate brewery in Dublin and is driven 90 miles to east Belfast where it is canned and then sent back to Dublin Port for onward distribution, said any friction, including a hard border could add on costs which could be passed onto the consumer.
It also said that its Baileys brand makes three trips to and from Northern Ireland and could also be prone to costs if the usual seamless production operation faces challenges.
Aodhan Connolly, director of the Northern Ireland Retail Consortium, said for consumer affordability, zero tariffs and quotas are the only way.
He added: "We have always argued that is necessary for unfettered access from NI to both the EU and GB markets to allow us to continue to provide NI and GB households with choice and affordability.
"The UKIM Bill does not solve these problems. For us there are only two shows in town to remove friction and keep costs down. We need some generous and sensible decisions from the Joint Committee and we need a UK-EU Free Trade Agreement which needs to have zero tariffs and zero quotas and be as comprehensive as possible."