Analysis: A case which must untangle the powers of court and parliament
John A Costello was walking along the quays in Dublin one morning in the mid-1960s when he bumped into a young Michael O'Kennedy.
The former Fine Gael Taoiseach and veteran barrister greeted the young Fianna Fáil Senator and fledgling barrister warmly as they fell into step, walking towards the Four Courts.
"Ah sure it's grand really, having a foot in the two mad houses. I mean if you get thrown out of one mad house you can always go back to the other one," Kennedy years later recalled Costello musing.