Fianna Fáil TD James O'Connor has called for the party to deal with its standing in the polls with a "greater degree of seriousness".
Speaking on the RTÉ News Your Politics podcast, he said: "We need to have a good hard look at our current trajectory."
The 23-year-old TD, who is the youngest member of the Dáil, said the party's popularity had fallen from 28% to 14%.
He said the party is "seen as being out of touch" and the party needed to return to its republican roots at a time when he believed the possibility of a united Ireland is growing stronger.
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