Opinion

John Liu, sock puppet

When the United Federation of Teach ers came knocking on Public Advo cate Bill de Blasio’s door for help last month, he turned over his official Web site to the union.

What a piker that de Blasio.

Comptroller John Liu has delivered his entire office to organized labor — without a qualm or even a blush.

Last week, he assured New Yorkers that public-employee pensions aren’t such a big deal — in contradiction of all the evidence and sure to astonish virtually every expert on the subject.

And it’s not just pensions.

Last month, he intervened on behalf of 3,400 unionized health-care employees in a dispute with Brooklyn’s Brookdale Hospital — demanding, with no legitimate standing whatsoever, that hospital managers step down.

Then, last Wednesday, he trotted out a Bangladeshi activist to claim that Walmart buys goods made with sweatshop labor — part of Liu’s endless campaign to block the popular retailer from opening stores in New York.

Technically, he’s hectoring the retailer as a “concerned investor”: He steers New York’s pension funds, which hold $305 million in Walmart shares.

But why focus on Walmart alone?

Those same pension funds have hundreds of millions invested with Apple, whose popular products are assembled in a sprawling factory complex in China where buildings are draped with suicide nets to prevent miserable workers from jumping to their deaths.

Why hasn’t Liu gone after them? Because Walmart is the white whale — Big Labor’s biggest obsession. And John Liu is now the point of its harpoon.

Meanwhile, Liu just released his third audit of the Department of Education, a study that undercuts teacher-accountability standards that drive unions mad.

He’s got nine more such audits in the works. Imagine the joyful anticipation at teacher-union headquarters.

The fact is, however, he wasn’t elected to serve as a hit man for New York’s unions. His job is to protect the fiscal well-being of the city. Every moment he forgets that does New York lasting harm.

Liu, who has all the backbone of a sock puppet, has designs on the mayoralty. But his record to date calls into serious question his fitness for the high office he already holds.