”FORGIVE me!” That’s the plea onetime radical Jane Fonda made to frail Nancy Reagan after portraying the beloved former first lady in “The Butler.”

But sources say that, while 92-year-old Nancy approved of Jane’s acting job in the critically acclaimed movie, she will NEVER forgive Fonda for her real-life role as “Hanoi Jane.”

A fierce opponent of the Vietnam War, the actress traveled to North Vietnam and was photographed sitting on an enemy anti-aircraft gun, seeming to support the communists.

“Nancy will never forgive or forget what Fonda did because she knows that President Reagan would never forgive her,” revealed a source close to the family.

“So many U.S. servicemen died for our country in the war, and Jane is still viewed as a traitor by many vets.”

MEANWHILE, critics have raved about “The Butler,” the fiction­alized story of longtime White House butler Eugene Allen, who served under eight presidents.

But Fonda, 75, seemed to be back to her old ways when she did a promotional interview for the film and wore a “Hanoi Jane” T-shirt – showing her back in the day with a clenched, raised fist.

“If Nancy had any lingering thoughts about forgiving Jane, those were erased by her wear­ing that shirt,” said the source.

“It was a slap in the face   to Nancy – and to Ronnie!”