Mary Lou McDonald says Tuesday's no-confidence vote in the Government is a chance for Ireland's politicians to 'stand up and be counted'.
The Sinn Fein leader today insisted the current Government had run out of road and said it was their job as leaders of the opposition to 'call them out'.
The Government lost its formal majority last week over fallout from the Mica controversy.
Deputy McDonald says it was the final straw in a long list of sins.
"It's now a decisive moment and people need to decide what they are going to do.
"I think it's a choice between saying this is a successful government who should carry on, which to me is unthinkable, or this is clearly shambolic and they're out of time and now we call that and name that in the Dail."