The independent public information campaign on the Lisbon Treaty has been launched in Dublin.
The Referendum Commission has begun distributing over two million copies of its hand-book to homes around the country.
More than twenty different types of ads will run on billboards, in newspapers, on radio and TV and on public transport.
The Commission is also targeting young voters by explaining the Lisbon Treaty through Bebo, Facebook and Youtube.
The information campaign is to cost up to €5m.