It used to be a given that Ireland was what some political scientists called a two-and-a-half party system, with the two parties that had emerged from the bloody civil wars of the twenties, Fianna Fail and Fine Gael, the Tweedledum and Tweedledee of Irish politics, and Irish Labour destined to play a poor third as occasional coalition partner.
Fianna Fail always had a dodgier reputation, exacerbated by Charlie Haughey's appalling corruption, but it had also become the natural party of government, a position recently crystallised by Bertie Ahern's decade in power. Even if there were two big parties, Fianna Fail was always the larger of the two.
And that's the context in which to read this morning's extraordinary Irish Times opinion poll. For the first time in history, the Irish Labour Party on 24% has overtaken Fianna Fail at 22% and pushed the party of DeValera into third place, with Fine Gael in the lead on a reduced 32% (Sinn Fein, the Greens and Independents get 8%, 4% and 9% respectively). Brian Cowen, whose abysmal leadership of his party has been marked by an approach to the economy similar to that advocated by David Cameron and George Osborne, has begun to kill his party.
Fianna Fail used to be a bit dodgy; it was never politically inept before. After huge public spending cuts and efforts to take medical cards from pensioners, satisfaction with the Government is just 14%, and Fianna Fail support in Dublin a mere 13%. Labour has had its false dawns before: it reached similar levels of popularity under Dick Spring in the early 90s but lost it by going into coalition with Fianna Fail; and it had a few heady years in the 60s too. But its leader Eamon Gilmore has had a good recession, and the polling speaks for itself.
There is only one phrase to describe what's happening in Irish politics today - that coined by the late Conor Cruise O'Brien in different circumstances - grotesque, unbelievable, bizarre and unprecedented or GUBU.
This post was picked up by Chris Paul and Politics in Ireland.