On Friday, MTA Chair Tom Prendergast used the occasion of a G train derailment to badger Bill de Blasio about upping the city’s contribution to the MTA capital program. His statement resembled the reaction from the TWU, beneficiaries of generous contract terms bestowed by Governor Andrew Cuomo last year. Prendergast delivered the same message on Sunday at the opening of the 7 train station on the far West Side.

It’s all part of Team Cuomo’s effort to dodge responsibility for the capital program. The governor has done his part by promising to fill most of the gap, the message goes, and now City Hall needs to step up.

The thing is, Cuomo has never explained exactly how he’ll close the gap, and any concrete proposal won’t be public until next year. You just have to trust him.

So why is it incumbent on de Blasio to commit funds to the MTA before Cuomo offers any specifics of his own? Who cares! The point is that in the meantime, while we’re waiting for details from the governor, Cuomo can use his surrogates at the MTA to bludgeon the mayor.

For anyone paying attention, the whole episode this weekend was just more proof that the MTA and Prendergast answer to Cuomo. (Note that the MTA chair never calls the governor to account. When Cuomo set up a recurring $30 million annual raid of the MTA operating budget, Prendergast said that was fine because the agency’s “needs are being met.”)

There’s nothing especially surprising about an appointee like Prendergast loyally serving the politician who selected him. But it’s jarring when the MTA chair is beholden to a governor with so little interest in improving the transit system and so much fervor for humiliating rivals.