Two separate meetings due to take place tomorrow involving ministers from both sides of the border have been cancelled due to a row over parades.
The North South Ministerial meeting in Dublin Castle has been cancelled after the DUP and the UUP withdrew from all-party talks.
Their withdrawal came as a result of a decision of Northern Ireland's Parades Commission.
The commission decided not to allow a controversial Orange Order march past the nationalist Ardoyne on its return route.
The commission said the potential for public disorder would be disproportionate to the significance of the march processing all of its route.
The Orange Order described the decision as preposterous and a reckless action.
The ban has led to the unionist parties withdrawing from the talks at Stormont, which had been aimed at seeking a resolution to the controversial issues of flags and parading.
Tánaiste Eamon Gilmore expressed his disappointment at the cancellation of the North South Ministerial meeting.
Mr Gilmore said he hoped it was "only a temporary setback and all parties will return to the talks as early as possible".
A separate function involving Minister for Transport Leo Varadkar and the North's Minister for Regional Development, Danny Kennedy, has also been cancelled.
The Parades Commission had allowed the morning portion of the march on 12 July along the Crumlin Road go ahead.
However, it ruled that the return in the evening will not be allowed.
The Parades Commission said: "It had considered the impact on community life and community relations and the potential for public disorder and had determined that these potential impacts would be disproportionate to the significance of this parade processing the entirety of its notified route."
When an Orange Order march through the nationalist Ardoyne area was banned last year it provoked widespread rioting.
It also resulted in scores of PSNI officers being injured.