An heir to the Gambino crime family has issued a stark warning to Michael Cohen, predicting that President Trump’s former personal attorney may face retaliation behind bars over his Congressional testimony.

‘A message for Michael Cohen: He better keep his mouth shut,’ Giovanni Gambino told the Daily Mail today, blasting Trump’s former fixer on the day he testified.

Giovanni, the 43-year-old son of late Sicilian mob boss Francesco ‘Ciccio’ Gambino and cousin to infamous crime boss Carlo Gambino, speculated that Cohen’s withering testimony could have harsh consequences.

‘Inmates love Trump, and hate rats. If he wants to get out alive, he better keep his mouth shut about Trump,’ Giovanni said.

The Gambino crime family is one of the “Five Families” that dominate organized crime activities in New York City.

Its illicit activities include labor and construction racketeering, gambling, loansharking, extortion, money laundering, prostitution, and fraud.

Cohen is due to report to federal prison in May.

He has been sentenced to serve three years after pleading guilty to campaign finance violations, tax fraud, bank fraud and lying to Congress.

In his prepared testimony on Wednesday, Cohen directly accused his former boss of bigotry, dishonesty, and possibly criminal conduct.

‘He is a racist, he is a conman and he is a cheat,’ Cohen told the House Oversight and Reform Committee in stunning testimony.

The prediction by Gambino came a day after Rep. Matt Gaetz (R-FL) tweeted a threat to Cohen on the eve of his public testimony before the House Oversight Committee.

Gaetz made an appearance at the hearing today, even though he had no role on it.

The Florida Bar has launched a probe into whether Gaetz violated professional conduct rules.

Last December, Trump applied the term “rat” to Cohen, who told a federal court that the president had directed him in violating campaign finance law, including by buying the silence of two women who claimed to have had affairs with Trump before he became president.

Remember, Michael Cohen only became a “Rat” after the FBI did something which was absolutely unthinkable & unheard of until the Witch Hunt was illegally started. They BROKE INTO AN ATTORNEY’S OFFICE! Why didn’t they break into the DNC to get the Server, or Crooked’s office?

— Donald J. Trump (@realDonaldTrump) December 16, 2018

The use of the rodent name for is someone who “secretly aids the police to apprehend criminals.”

Experts date its use in the “underworld” — the abode of criminals and organized crime — to 1902, while it began to be employed by police in the 1920s, as they squeezed the underlings of gangsters and mafia bosses enriching themselves in the illicit liquor trade.

It is most associated with infamous mob boss Al Capone.

Giovanni agreed with Trump’s assessment.

‘President Trump is right by calling Cohen a Rat,’ Giovanni said. ‘Cohen unnecessarily lied to the FBI and stupidly incriminated himself.’

‘Unfortunately he might face the same fate as Whitey Bulger,’ Giovanni added, referring to the infamous Boston crime boss turned FBI informant.

In October, Bulger was brutally killed inside a federal prison in West Virginia in a suspected mafia hit.

Cohen addressed the allegation that he is a ‘rat’ in his testimony on Wednesday, saying: ‘I have been smeared as a rat by the President of the United States. The truth is much different … I have always tried to live a life of loyalty, friendship, generosity and compassion.’

On May 6, Cohen is scheduled to report to prison to serve his 36-month sentence.