War of the former First Ladies as feud between NANCY REAGAN and LAURA BUSH erupts!

Laura Bush’s candid new memoir has got oh-so-prim and proper Nancy Reagan in a snit – and Nancy is blasting the book as a crass bid for publicity!

With Laura promoting Spoken from the Heart on a national book tour, a huge rift has erupted between the former first ladies.

"Nancy thinks it is unseemly that Laura told so much in the book," an insider told The ENQUIRER.

 "And Laura thinks Nancy’ s become an old biddy who should mind her own business."

In one of the memoir’s most shocking revelations, Laura comes clean about the 1963 car crash, claiming the life of a close friend.

Laura, 63, also details her husband’s heavy drinking, saying: "It was lethal."

Still spry at 88, Nancy called it "shameful and undignified" that Laura would share such personal agonies with the public, said a source close to her.

"Nancy told me, ‘It’s definitely not what I think a first lady should do. This is simply an embarrassment,’" the source divulged.

 But according to sources, when Laura learned about Nancy’s criticism, she scoffed at her pomposity!

"Laura feels Nancy kept the White House as an ivory tower. Laura said she wouldn’t dream of emulating Nancy’s style," said the source.

"Laura’s been enjoying the attention of the book tour, and she feels Nancy’s become cranky in her old age."