“A gas shortage threatens the Long Island region,” bleat six Long Island state senators, all Democrats, in a letter pleading for approval of a pipeline proposed to fix the problem — belatedly admitting that the policies they’ve long favored don’t work for their own constituents.

This year, Sens. Todd Kaminsky, John Brooks, James Gaughran, Anna Kaplan, Monica Martinez and Kevin Thomas all voted for Gov. Andrew Cuomo’s Green New Deal law, whose very purpose is to further crimp energy supplies, and for a $100 million hike in taxes on energy.

And, as Senate GOP leader John Flanagan (their fellow Long Islander) notes, all were AWOL when the Williams pipeline was up for consideration by the state Department of Environmental Conservation — which recently issued a pseudo-scientific veto of the project.

Or maybe anti-scientific is the right word: The DEC pretends the Williams pipeline is a threat to water quality. But it would run under New York Harbor roughly parallel to an existing pipeline (now at capacity).

The “lack of a reliable future natural-gas supply has the potential to upend the lives . . . halt economic development, and adversely result in the use of dirtier forms of energy,” the Democrats write in begging for “emergency” approval of the pipeline.

Of course it does. But the Long Island Six, like most New York Democratic electeds, have long pretended otherwise.

Kaminsky, for example, chairs the Senate’s Environmental Conservation Committee, and sponsored a recent bill to “prohibit oil- and natural-gas drilling in New York’s coastal area” and “restrict the power of . . . corporations to develop pipelines associated with the delivery of natural gas or oil” in or even near the state.

Never mind that National Grid, the utility for the area, warned this summer that it was unable to deliver more natural gas to Long Island unless the state OK’d the pipeline, and specifically said it would have to stop taking new customers.

Democrats from Cuomo on down treated that as a bluff, or a threat — and then turned around and blamed the utility when it followed through.

But now Winter Is Coming. The Democratic county executives of Nassau and Suffolk have belatedly called for the pipeline to go through, and joined the business community in pleading for support of the six senators.

Hence their belated plea for approval of the pipeline: “National Grid’s moratorium has already impacted thousands of our constituents,” they complain — as if their own policies hadn’t forced the moratorium.

But just this one. “This is the last gas pipeline that will merit your review as our state transitions to a renewable-energy economy,” they write. Guess any other part of New York (like Westchester) that faces similar issues is just plumb out of luck.

What a pathetic pack of hypocrites.