Fine Gael spent more than any other party in last year's elections for the European Parliament, a report from the Standards in Public Office Commission shows.
The party spent €1,041,846 when Frances Fitzgerald, Maria Walsh, Mairead McGuinness and Seán Kelly took seats.
The next biggest spending party was Fianna Fáil which put €794,768 into the election that saw Billy Kelleher take a seat.
Sinn Féin spent €308,677 when Matt Carthy took a seat before he ran successfully in this year's General Election and was replaced by Chris MacManus in Brussels.
The Green Party spent €154,832 and took two seats with Ciaran Cuffe and Grace O'Sullivan joining the European Parliament.
Independents4Change won two seats as Mick Wallace and Clare Daly joined the European Parliament.
They put €76,782 into their campaign.