If the results go as predicted today the Labour party leader Joan Burton looks certain to face a leadership heave.
Under Labour's constitution, a leadership contest must be held within six months of failing to get into Government.
Tallies suggest Labour will poll under 8%, far below their 2011 performance.
Former Labour director Tony Heffernan said: "There has to be a leadership contest within six months, if Labour do not go back into government.
"It looks pretty obvious that Labour are not going to be involved in the formation of whatever government emerges from this.
"The Labour party will need to take some time out and reflect on what has happened and on the lessons of the last five years."