When Gov. Andrew Cuomo recently signed a bill making it harder for government workers to escape labor unions, he said it was just “the first step of the resistance.”

Translation: It wasn’t the last favor Cuomo hopes to do for New York’s powerful public-sector unions in anticipation of the coming US Supreme Court decision in Janus v. AFSCME, which could void state laws compelling government workers to pay dues-like agency fees to unions they choose not to join.

The bill Cuomo signed is a wet, sloppy kiss for union leaders. It gives unions special powers to pressure people into joining, and then makes it extremely difficult for workers to leave if they change their mind.

What’s more, the unions no longer have to provide services for workers who are covered by their contracts but aren’t paying dues, despite having rigged the system to prevent these nonmembers from being represented by rival unions.

There’s little more Cuomo could do for unions short of subsidizing them directly.

Which, in fact, might be what he has in mind next.

At stake for New York in the Janus case are at least $862 million in annual revenues the unions now rake in from state and local government workers who, under current law, know they’ll be forced to pay even if they opt-out of membership.

Political allies of government unions, such as Mayor Bill de Blasio, argue “labor stability” relies on providing resources to the unions in the form of agency fees from nonmembers.

If the Supreme Court stops compulsory agency fee payments, the governor and legislators may well use the same rationale to justify subsidies of unions’ “representational” functions.

Consider, for example, what Hawaii state lawmakers proposed in 2016, when the Supreme Court seemed poised to end agency fees as part of its ruling in Friedrichs v. California Teachers Association (a case that ended in a draw after the sudden death of Justice Antonin Scalia).

Aloha State pols wanted to steer public money into a “public employees’ collective bargaining fund.” Their rationale? Ending the fees would “fundamentally undermine this legislature’s consistent efforts to ensure labor management peace.”

In reality, there is no evidence that agency fees contribute to “labor peace.”

In fact, the already high number of public-sector strikes in New York actually rose for several years after compulsory agency fees were authorized in 1977; strikes only dropped off in the early 1980s, in New York and across the country, after President Ronald Reagan’s high-profile firing of striking air-traffic controllers.

Subsidizing even a fraction of $862 million in union revenues wouldn’t just be expensive. It would also create new potential for misuse of public funds. After all, government unions have been caught miscategorizing expenses to conceal their political activity, and must disclose little about how they spend the money workers are forced to pay them. Nothing would stop the unions from routing public money into the same political uses.

When unions provide workers with real value for their dues payments, they won’t have trouble attracting and retaining members.

When they don’t, it shouldn’t be up to taxpayers to make up the difference — propping up organizations whose fundamental goal is to squeeze more money out of public budgets.

Beyond the dollars-and-cents impact, everything a government union does is inherently political — which is what brought the Janus case to the Supreme Court in the first place.

Our constitutional guarantees on free speech and free association mean no one can be forced to support a political cause they don’t agree with, whether they’re workers or taxpayers. Subsidizing government unions with public funds would do exactly that.

Cuomo has been fairly obviously scrambling to pander to labor unions ahead of September’s gubernatorial primary. It would be a shame if he stomped on the First Amendment in the process.