Independent MEP Nessa Childers has said she will not run as a candidate in the next European elections in 2019.
Ms Childers was first elected to Brussels as an MEP for Dublin in 2009.
In a statement, Ms Childers said she was making the announcement now as from September onwards MEPs enter a "pre-election phase."
She added that she will continue to work as an MEP until the end of her term in two years.
Ms Childers is one of three MEPs for Dublin, along with Lynn Boylan of Sinn Féin and Fine Gael's Brian Hayes.