Longtime Colombo under-boss John “Sonny” Franzese is the living embodiment of the ultimate mob rule — bragging in an interview about refusing to rat despite it making him the oldest federal prisoner at the age of 100.

Wheelchair-bound Franzese, now 102 and living in a nursing home, told Newsday about his life of crime — and how he stuck to the “Goodfellas” adage of “Never rat on your friends, and always keep your mouth shut” despite facing 50 years behind bars.

“They wanted me to roll all the time,” Franzese insisted. “I couldn’t do that. Because it’s my principle. I could never give a guy up because I knew what jail was. I wouldn’t put a dog in a jail pod.”

Speaking for the first time since his release in June 2017, Franzese bragged to the paper that “no one in history” had done as much, likening it to godliness.

“Jesus suffered,” he said. “He didn’t squeal on nobody.”

In an age where other mob bosses turned, his commitment also caught the attention of the late John Gotti, who called Franzese “one tough [expletive] guy” for his refusal to rat.

“He demanded so much respect because he did all that time and he never gave anyone up,” the late Bernard Welsh, an FBI agent who arrested Franzese for violating parole, once admitted.

Franzese’s commitment was so firm he reportedly went along with contracts on the lives of two of his sons who turned rat, though neither were killed.

One, John Jr., 58, even wore a wire and gave evidence against the Colombos and his dad, sending him back to jail when he was 93.

“I don’t know what happened to him,” the aging mobster told Newsday of the son who entered federal witness protection.

“Maybe all the drugs he took. Screwed his mind up.

“Listen, it broke my heart. He would be the last guy I thought would do that. But he did it.”

Franzese — who now has a pacemaker, hearing aids and a broken hip — had been tipped in the 1960s as a potential new Colombo boss.

He was linked by law enforcement to multimillion-dollar bookmaking, loan sharking and extortion rackets — and was even caught on tape seemingly alluding to multiple murders he claimed to have committed.

“I killed a lot of guys … you’re not talking about four, five, six, 10,” he allegedly said in a December 2006 conversation secretly taped by a mob associate.

Franzese did not seem shy in his interview about his role in the mob.

“What we done in New York is unbelievable,” he told Newsday.

“I wasn’t a guy that was afraid, you know. Don’t forget, I fought everybody.

“I was a good soldier,” he admitted.

He was also proud of the famous faces who became friends.

“I knew them all,” he said when asked about The Rat Pack, Dionne Warwick and Frank Sinatra.

“You asked the question the wrong way. You should have asked, ‘Did Frank Sinatra know Sonny Franzese?’”

Still, he insists a batch of charges in the 1960s — including the homicide of a one-eyed hitman from Long Island — were a “conspiracy to get me.”

“There is no question about it,” he told Newsday.

He beat all the cases but for conspiracy to rob banks across the country and was sentenced to 50 years in prison.

“Never happened,” Franzese insisted to Newsday. “It ain’t right for something I’d never done.

“I’d have to be a nut to rob banks.”

He went to prison in Easter 1970 vowing “to do the whole bid” because “I didn’t want to rat on anybody.”

After being paroled in 1978, he returned to prison five more times as he repeatedly violated his parole by associating with fellow mobsters.

He was 93 when he was sentenced in 2010 to eight more years after being convicted of extorting clubs, including the Hustler and Penthouse strip clubs in Manhattan, in part on tapes made by his son John Jr.

Despite spending more than a third of his life in prison, he insists, “I hate everything about it.”

“I’ll meet them in hell,” he said of the prosecutors and judges who sent him to prison, insisting, “I never hurt nobody that was innocent.”