Originally Posted by
paul2
Irish (Rep of)Immigration will be cleared at Dublin airport and there is freedom of movement for anyone throughout the island of Ireland after that. There is no complication whatsoever.
This is incorrect. Not all third country nationals have an automatic right to travel freely in the common travel area (see the legislation referenced by
Christopher). An Irish immigration officer cannot give you leave to enter the UK and if your immigration status requires such a leave (typically: if you need a visa), you need to enter the UK via a UK port of entry rather than across land borders in the common travel area.
Originally Posted by
Christopher
However, although this provision exists, the situation does not arise as airports are presently set up, since, as noted above, there is no routine immigration control between the Republic of Ireland and Northern Ireland and anyone transferring from an international flight on to a Belfast-bound flight would pass through immigration.
It has been a very long time since there were flights between Dublin and Belfast. There were flights between Cork and Belfast and between Dublin and Derry. Not sure whether either service still exists. As a matter of principle, however, what you say is right.
Originally Posted by
Christopher
There are, however, sometimes ad-hoc controls at the border
In the hundreds of times I have travelled between Dublin and Belfast in the last ten years, whether by train or by car, I have yet to be subject to cross-border immigration checks. The only period I was regularly stopped at the border was during the foot and mouth epidemic but the controls were just to check whether animal products were carried rather than for immigration purposes. What would have a greater likelihood of happening is being nipped by the NIPS for a motoring-related offence (eg speeding) or some other non-immigration related random control.