The Foreign Affairs Minister Simon Coveney has said Northern Ireland's DUP are offering 'problems but no solutions' to the Northern Ireland Protocol.
It comes as the North's First and Deputy First Ministers will hold talks with the European Commission and the British government on Wednesday over security concerns at two ports.
Some animal and food checks at Larne and Belfast were stopped, after graffiti opposing the Irish Sea border was painted in loyalist areas.
There were fears for the safety of staff.
On Tuesday night the DUP called on all unionist parties to unite and undermine the Northern Ireland Protocol.
Minister Coveney told Newstalk Breakfast this is nothing new from the party.
"Let's not forget the context here: Brexit is the problem that's causing all of this disruption.
"The protocol was designed to try to limit that disruption on the island of Ireland and in Northern Ireland".
"But not for the first time, the DUP are outlining problems but no solutions.
"I mean lets not forget: the DUP are a party that actually led the calls for Brexit in Northern Ireland.
"They then rejected solutions that would have been far easier for Northern Ireland to adopt".
He said this included the party rejecting the idea of the UK staying in the EU customs union, as well as the backstop.
Mr Coveney said he accepts that there are 'practical implementation problems' with the protocol, and they are looking for solutions.
'Protocol is part of international law'
Host Shane Coleman suggested the DUP 'have a bee in their bonnet' on the issue, Mr Coveney replied: "When have the DUP not had a bee in their bonnet when it comes to Brexit, and the kind of Brexit that they want?"
He said one party cannot take away a piece of international legislation.
"The idea that we can just do away with the protocol, I think is unrealistic, because what are we going to replace it with?
"I haven't heard anybody who criticises the protocol come up with a credible alternative to it.
"And let's not forget: the protocol is now part of international law, it's part of British law, and so you can't just simply do away with it".
He also said events last Friday, which saw the European Commission threaten to tighten rules on exports, did not help the situation.
"Of course this is a worry, the safety of staff must come first and that's what happened yesterday.
"I think there is some uncertainty as to the level of threat that's there - certainly the PSNI have confirmed that this does not involve loyalist paramilitaries.
"But clearly there is lot of tension, and Friday didn't help that, when the [European] Commission made a serious mistake by signaling an intention to trigger Article 16 of the protocol - that should not have happened.
"They reversed that decision quickly, but certainly on the back of that it sparked a lot of tension in Northern Ireland - and my job is to try to calm that".
