Former Taoiseach Garret FitzGerald will join Fine Gael leader Enda Kenny today for a special event to mark Europe Day.
The briefing will support a Yes vote in the upcoming Lisbon referendum on EU reform.
The pair will also be joined by former European Commissioner and world trade chief Peter Sutherland as well as Dublin MEP and director of elections for the Lisbon Treaty Campaign Gay Mitchell.
Meanwhile, the European Commission offices in Dublin will also hold a free lunchtime concert to mark the day.
Performers will include prize-winners from the Feis Ceol, including mezzo-soprano Naomi O'Connell and tenor Dean Power.
Europe Day, May 9, marks the anniversary of the day in 1950 when the European Union was conceived.
French foreign minister Robert Schuman gave a speech calling for European countries to combine their coal and steel production under a single European institution, paving the way for our current European Union.