Tony Wootton and Gwen Zanzottera give us the origin of the phrase – “A Mop Fair”. This phrase is not used very commonly in this part of the world but it does one no harm to know an extra phrase.
“A Mop Fair”
In many places in the UK the annual fair is known as ‘The Mop’, and this is a shortenend form of the ‘Mop Fair’. Anyone looking forward for work would at one time line up at The Mop and they would carry the tools of their trade, that was, a milking stool, a bag of carpenter’s tools, or a mop. They would be inspected by the employers who walked along the line, and then offered a job.
In some places, there would be a Runaway Mop about two weeks later and this was for anyone hired at the Mop who did not like their employer. They could run away and line up at the Runaway Mop to see if they could find a better job.