The Taoiseach says exempting rich people from the upcoming electricity credit would take time.
It comes after Ryanair boss Michael O'Leary said people like him shouldn't be getting the universal Government support.
Micheál Martin says he agrees with Michael O'Leary that there shouldn't be energy subsidies for rich people like the airline boss.
His comments come ahead of a cost of living protest in Cork city this weekend.
The Cost of Living Campaign is made up of local opposition politicians, student groups, disability service advocates and charity groups who say they have little confidence in the Government's ability to ease the pressure on those struggling with rising prices.
Taoiseach Micheál Martin says he agrees the rich shouldn't benefit, but working out a means test would take time.