He made the announcement in a 22-minute televised address, during which he once again sought to cast the attorney general's documentation of sexual harassment and groping as politically motivated.

"I think that given the circumstances, the best way I can help now is if I step aside," Cuomo said from his Midtown office, telling New Yorkers that he would step down because of the time and toll a previously promised fight to stay in office would take.

Cuomo's resignation marks an ignominious end to the Democrat's three-term run as governor, the same number of terms to which his late father — Gov. Mario Cuomo, whom the younger Cuomo idolized — was elected. 

By resigning before his term ends, Andrew Cuomo will not match the three full terms as governor that the family patriarch served. 

"This is one of the most challenging times for government in a generation," said the outgoing governor. "Government really needs to function today, government needs to perform. It is a matter of life and death."

"Wasting energy on distractions is the last thing [the] state government should be doing."

The impeachment fight, he said, would "consume government."

"It will cost the taxpayers millions of dollars," he went on. "It will brutalize people."

"This situation, by its current trajectory, will generate months of political and legal controversy. That is what we're going to have. That is how the political wind is blowing."

Cuomo went 11 minutes into the speech before making the stunning announcement, which made him the third New York governor in a row to be forced out of office amid scandal after David Paterson and Eliot Spitzer.