Mike Bloomberg is an amazement.

He spent more than $160 million to become and remain mayor — not counting the off-the-official-books millions dispatched to strategically situated charities and such.

And it’s likely he’ll have tossed another $100-plus million into the pot before Election Day.

But now he’s lecturing New York on the need for campaign-finance reform.

Simply breathtaking.

Sure, Mike came by his dough honestly, and he should be free to spend it. Period.

And campaign-finance “reform” as it has evolved in New York is a crock: Unions essentially are exempt from the rules, and everyone else is not.

One predictable result: Those City Council members deemed too dumb to remember their pro-union lines now read them from union-produced cue cards as they “debate” union-friendly legislation during ostensibly “public” meetings.

So, by all means, let’s “reform” the system — starting, it is to be hoped, with the union exemptions.

Still, while Mayor Mike brings much to commend him to the present debate, standing to hector New Yorkers about campaign finance is not among them.

Really.