This melody is the vamp Johnny Moynihan adds at the end of "Waxies Dargle" by Sweeney's Men. He has in recent concerts sung a bit of the last verse for comedic effect,
"For up to heavens I will take my lay
The angels, too, will sing... What'll you have, will you have a pint, will you have a pint with me sir,..."
In the original Waxies Dargle it's played on the mandolin and bouzouki with very heavy tremolo, many people maybe remembered the song and the last lines, which would have ended: "The angels too will say TIME, GENTLEMEN, PLEASE!"