The three candidates were all asked about their views on the presidency on RTE Radio, in the first series of broadcast interviews after the deadline for nominations closed at noon on Wednesday.
Fianna Fail candidate Jim Gavin and Fine Gael candidate Heather Humphreys filed their nomination papers last Friday. Independent candidate Catherine Connolly, who is supported by left-wing parties Sinn Fein, the Social Democrats, Labour, People Before Profit and the Greens, submitted the documentation on Tuesday.