A row has reportedly broken out within the Fianna Fáil party ahead of the Carlow-Kilkenny by-election on Friday.

Fewer than 33 members of the parliamentary party showed up to a special meeting in Kilkenny on Monday to support their candidate Bobby Aylward.

According to the Sunday Times, Aylward's Director of Elections Barry Cowen has since written to members warning Fianna Fail will lose the by-election without more party involvement.

Micheál Martin's party has lost all six by-elections since the last general election.

They've also been criticised internally for their lack of involvement in canvassing for a Yes vote in the same-sex marriage referendum.