The Tánaiste says tens of thousands of jobs may be lost in Ireland as a result of Brexit.
Simon Coveney said he knows people are bored listening to warnings about Brexit, but there are still real risks to the economy.
The European Parliament is today set to approve the Withdrawal Agreement, paving the way for trade talks to begin.
With the UK set to officially leave the bloc at 11 pm on Friday night, there will then be an 11-month transition period to allow for the discussions on the 'future relationship'.
British Prime Minister Boris Johnson has ruled out extending the transition period beyond December - prompting warnings from senior EU figures that not every aspect of an agreement will be able to be agreed by the end of the year.
Speaking on his way into a Cabinet meeting this morning, Minister Coveney said that there is no guarantee a deal will be reached.
He observed: "We are potentially still preparing for a 'no deal' on trade with the UK.
"[That] involves significant contingency and planning potentially for tens of thousands of job losses in vulnerable sectors like agriculture, agri-food, fisheries, tourism and so on.
"That is why - despite the reality that many people are bored of listening to me on Brexit and of talking about Brexit, just like many people in the UK are too... - the truth is Brexit is far from done, and there are real, real risks for Ireland in the next round of Brexit."
The Tánaiste added: "Regardless of what happens at the ballot box, people will be thinking about Brexit when the begin to realise the realities of the consequences of the negotiations.
"For the next year, we will see Brexit issues continue to dominate Irish politics."