The Gasman Cometh by Flanders and Swann

It starts;
'Twas on a Monday morning the gas man came to call.
The gas tap wouldn't turn - I wasn't getting gas at all.

and leads up to;
On Saturday and Sunday they do no work at all;
So 'twas on a Monday morning that the gasman came to call...

As usual, Michael Flanders wrote the words, while in his memoir his partner said, "I took the tune from 'Dashing Away With A Smoothing Iron,' and simply changed it a little bit, just enough to make it copyright Donald Swann! But it is really based on a Folk song."