Just to confirm that he’d rather play political games than help get the subways fixed, Mayor de Blasio over the weekend dropped a “plan” to tax the city’s rich to get the MTA more cash.

Naturally, it’s something he can’t actually do himself: The Legislature and Gov. Cuomo would have to change state law.

And never mind he’s been claiming the subways aren’t his responsibility, or that he utterly ignored them (including never riding the trains) until the crisis struck — and then went into blame-everyone-else mode.

Or that he’s now contradicting the main argument he’s been making, namely that the city is already covering its fair share of the MTA’s budget, since the new revenue would come entirely from the five boroughs.

Or that the agency needs reliable streams of revenue — while income-tax collection from the rich is one of the most unstable sources of cash. (A bad year for Wall Street bonuses, and it plummets.)

No: Plainly, all the mayor cares about is signaling his own progressive virtue with yet another version of a tax hike he’s been pushing for years.

Actually, he likely sees this as a two-fer, since he thinks it’ll cause political trouble for folks he hates with a passion: Gov. Cuomo and the leaders of the state Senate.

In other words, his “solution” is entirely self-serving, not any practical compromise to resolve a crisis that’s creating daily hell for his constituents.

And of course it comes with de Blasio’s trademark bull: “We are asking the wealthiest in our city to chip in a little extra,” his statement claimed. No, a tax hike isn’t “asking,” it’s ordering. “Asking” would be a call for donations.

(The problems of one in-between approach, selling the right to name a station after your company, were humorously exposed over the weekend when the porn channel RedTube said it would love to be a sponsor.)

Yes, Cuomo is playing politics here, too: His promises of new MTA cash are utterly vague, and it’s his pick for MTA chairman, Joe Lhota, who put the idea of a 50-50 state-city split of the emergency-funds bill on the table.

But Cuomo has also taken real steps toward fixing things, putting the universally respected Lhota in charge and adding the highly competent Pat Foye to the MTA’s leadership team. All de Blasio has done is hold a (disastrous) press conference and issue statements about what other leaders should do.

If the mayor wants anyone to take him seriously, he should come up with a few things he’s going to do to help out.

Quit kibitzing from the peanut gallery, and be a leader.