Mrs Robinson with Bono will help the Taoiseach and Tánaiste launch the campaign on Monday.
Bono has sung the praises of Leo Varadkar in a series of gushing letters hailing him a 21st-century leader.
Bono introduced Leo Varadkar to Noel Gallagher at a party at his home.
Taoiseach Leo Varadkar has a fan in [email protected] frontman Bono, who called him inspiring.
The actor jetted in with wife, Amal on Saturday and enjoyed a family reunion with his Irish cousins and parents in Laois.