Rearrange the parts of the sentence in correct order.
So, increasingly,
P-paying to provide revenues
Q-for the Central government
R-the poor have been

Let's track the syntax of the components:
The opening introductory phrase is "So, increasingly," which needs a subject and verb to follow. Part R provides the subject and auxiliary verb: "the poor have been".

After "have been" in a continuous sense, a participle (verb+ing) can follow. Part P gives "paying to provide revenues".

Part Q finishes the prepositional requirement of "revenues": "for the Central government".

Putting it together sequentially creates the meaningful sentence: RPQ ("So, increasingly, the poor have been paying to provide revenues for the Central government.")