How do you know Gov. Andrew Cuomo has realized a policy is a political loser? Watch for him to start claiming someone else is responsible.

Thus his comment in an interview last week about how the “political decision” of OK’ing a pipeline to ease the Brooklyn and Long Island natural gas shortage “will probably come down to the state Legislature.”

Bull: It’s Cuomo’s Department of Environmental Conservation that blocked the Williams pipeline on spurious water quality grounds. (Yes, spurious: It would run next to another pipeline, built years ago with less advanced technology, that plainly didn’t poison New York’s water.)

Even if lawmakers changed how the DEC is to make such decisions, it’d still be the DEC’s call — and the DEC would still be doing exactly what the governor ordered.

Cuomo has plainly ordered up a near-total ban on new pipelines to win the favor of extreme greens. But that leaves businesses and homes stuck without access to natural gas and having to rely on higher-carbon fuels.

First, the gov blamed the relevant utility, National Grid; now he’s fingering the Legislature. If only he could find a way to pin the blame on Mayor Bill de Blasio …