I found this list of work songs that somebody posted for a previous Labor Day. Some are better than others, but there are some good ones I hadn't thought of myself (e.g. Dylan's "Maggie's Farm").
Some more obscure choices I would add to the list are:
Spot 1019 - Wild Wild Workweek
Nothing Painted Blue - Swivel chairs
Vehicle Flips - Expendable You
Lou Reed and John Cale - Work
Robert Wyatt - Age of Self
Redskins - Go Get Organised
Billy Bragg - Which Side Are You On
Pete Seeger - Which Side Are You On
Bill Monroe and the Bluegrass Boys - I'm Working On a Building
Eggs - Government Administrator
Lastly, an honorable mention goes to the Bill Laswell instrumental "Work Song" that was the WRCT radio calendar music for much of the 1980s.