The Democratic Unionists have warned the Irish Government to stop engaging in "megaphone diplomacy" as their row over Brexit continued.
DUP MP Jeffrey Donaldson urged Taoiseach Leo Varadkar and his Fine Gael party to "step back" from its increasingly robust stance on the UK's EU exit.
Relations between the two parties have frayed in recent weeks as Fine Gael have openly criticised the UK's attitude to resolving the issue of managing the Irish border post-Brexit.
The spat comes ahead of Mr Varadkar's first visit to Northern Ireland as Taoiseach at the end of the week.
Last week, the Fine Gael leader attempted to shift the onus for designing a solution to border movement firmly onto the UK, insisting he was not going to "design a border for the Brexiteers because they're the ones who want a border".
After the DUP criticised the Irish premier's remarks, Fine Gael senator Neale Richmond accused Northern Ireland's main unionist party of "whinging" and claimed it was politically "impotent".
Donaldson said the Dublin government had to re-engage in efforts to design ways to handle movement across the border.
"What won't solve the problem is megaphone diplomacy from Dublin," he said.
"I think the Taoiseach needs to recognise that going back to the politics of the 1970s and 80s in Anglo Irish relations isn't going to help anyone."
In an interview with BBC Radio Ulster, the Lagan Valley MP said: "We have to co-operate here. A solution has to be one that is agreed and that means Dublin has to have an input."
He added: "If Dublin refuses to co-operate on this inevitably we are going to end up in a different arrangement that could result in some sort of hard border.
"Now that's not in Dublin's interests - the Irish economy would suffer greatly if we can't find an agreed way forward.
"So I would say to the Taoiseach, who is coming to Belfast later in the week - he needs to be at the table."