A new opinion poll shows a significant drop in support for Fianna Fáil.

The Red C poll in the Sunday Business Post also finds that half of all voters do not trust the Government to manage the public finances out of the current downturn.

The poll, which was conducted on Monday, Tuesday and Wednesday, shows Fianna Fáil at 36%, down four points since its last poll in June.

Fine Gael has gained three points to 28%.

Labour is down one to nine, the Greens are unchanged at seven and Sinn Féin also drops one to nine.

The Progressive Democrats have seen a slight rise in support. While the poll was being conducted this week, PD leader Ciaran Cannon said the party was no longer politically viable, but support has gone up by one point, to 3%.

Concern about the economy is the most likely reason for the drop in support for Fianna Fáil.

When asked if they were confident the Government could manage the public finances out of the current downturn, just 39% of those polled said they were confident, while 50% were not, and 11% did not know.