Fianna Fáil has seen its support plunge in the latest Sunday Business Post/Red C poll while support for Fine Gael and Sinn Féin is up.

There is also alarming news for Minister for Transport Shane Ross and the Independent Alliance, who have slumped to 1 per cent - their lowest support level ever in a Red C poll.

Fianna Fáil had been on a high last month after its strong challenge...