City Comptroller John Liu clings to office at the end of a week that saw his campaign finance director arrested and the FBI deepening its investigation into his star-crossed mayoral campaign.

Whether Liu believes he can actually function in the job (he can’t), or just views it as a plea-bargaining chip should the feds narrow their focus to him, is anybody’s guess.

But Gov. Cuomo needs to be thinking about how to spare the city further drama.

The City Charter allows the governor to immediately suspend Liu for 30 days — and to remove him entirely by bringing malfeasance charges.

The feds say Liu’s campaign was a virtual engine of corruption — developing networks of straw donors to hide the real sources of illegal, oversized contributions from wealthy backers.

An allegation, of course, is not a conviction. Liu has yet to be charged with a crime.

But it remains that Liu holds the most sensitive job in city government. He’s responsible for oversight of billions upon billions of public dollars — and yet he claims that he was shocked by his aide’s arrest.

But no reasonable person can believe that she was a free agent in that fraud.

Where will the bucks stop?

Cuomo needn’t wait to find out. The charter lets the governor turn the reins over to the first deputy comptroller while a special election is arranged.

True, Liu can’t be expelled until he has “an opportunity to be heard in his defense” at a public hearing.

We can only imagine what he’d say:

I’m not a crook — even if all my friends and staffers and finances are dirty.

This week, Cuomo touted how clean the state has been on his watch: “It has been 14 months since the governor of the state was indicted or admitted committing major felonies. . . We have now gone three months without a conviction of a sitting legislator.”

But that’s Albany. Time to take up the cudgels in the city, Governor.