I think so. The wiki article for the Irish Labour Party http://ga.wikipedia.org/wiki/P%C3%A1irt%C3%AD_an_Lucht_Oibre_(%C3%89ire) describes the political ideology as "an eite chlé" or left-wing
Note that the FGB doesn't actually translate [ó] as "to" - it translates ó thuaidh as "northwards", which we usually understand as "to the north".
"eastward(s)" is soir and "westward(s)" is siar - they reflect the more familiar suas/thuas/anuas structure.
Here's a thought: The best-laid plans of mice and men gang oft agley. Left in Scots Gaelic is pretty similar - clì. I wonder if agley might be taken from that, in the sense that "taking a left turn" can mean "going pear-shaped" or "going south." Wikipedia's etymology for agley doesn't match, but I wonder.