AP
Spitzer's comments came on MSNBC's "Hardball," after much prodding from liberal host Chris Matthews.
Spitzer first told Matthews that he would fire a government employee who engaged in Weiner's behavior. At the end of the interview, Matthews pressed Spitzer on who he was going to vote for in the Democratic primary for mayor.
Spitzer objected to answering that question, but Matthews then followed up and asked if it was fair to say Weiner should not be mayor.
"That's correct," Spitzer said.
Support for Weiner has been collapsing in recent polls, with a new Quinnipiac poll released Monday showing him plunging to last place among serious Democratic contenders.
Weiner admitted last week to online sexual relationships with at least three women after resigning from Congress in 2011. In total, he estimated that he had online relationships with between six and 10 women both during his time in Congress and otherwise.
Spitzer, of course, notoriously resigned as New York's governor in 2008 amid a prostitution scandal. He announced his candidacy for comptroller toward the beginning of the month.
In response, the campaign of Scott Stringer, Spitzer's Democratic opponent in the comptroller race, blasted Spitzer for an apparent double standard.
"It's clear that Eliot Spitzer thinks there are two standards – one for him, and one for everybody else," Stringer spokesman Audrey Gelman said in a statement. "His comments are the height of hypocrisy."
We'll update with a video clip when it's available.