Probably about the Taff Vale dispute.

"Will you walk upon my railway ?" said the spider to the fly ; [Note 573.1]
'Tis the handiest little railway that over you did spy ;
If you come I'll give you wages, as much as you require,
Find you with food and clothing to meet your heart's desire." [Note 573.2] 

But the wary fly made answer, "No, I see your little plan,
Your promise sounds most gracious, but you'll trick me if you can ;
'Tis the nature of the spider to take in the simple fly,
And ne'er to let him out again, until he's sucked him dry."

When the fly had finished speaking, then the spider turned and said,
"Very silly are these notions, which have filled your little head ;
If you think a little you will see there is no other way,
For this railway's mine, and, mark you, you can't live without some pay."

"Very true," the fly made answer, " I can very plainly see
That a choice of cruel spiders is the only choice for me,
So walk a little further, and maybe I shall find
In the world another Spider more suited to my mind,". [Note 573.3]