Former National leader Simon Bridges is releasing a book.

The Tauranga MP announced his book, National Identity: Confessions of an Outsider, on social media this evening.

Bridges described the book as "an open, honest and at times intensely personal memoir about race, fatherhood, marriage, masculinity, fitting in, and the things that shape our national character."

But according to the cover, it's "not a political memoir".

Commenters on his social media pages questioned if the book was an opportunity to win back the National Party leadership, held by Judith Collins - who wrote her book, Pull No Punches, when Bridges was leader.

"Look out Judith, someone's after your job!" said one person on Facebook.

"'Not a political memoir.' Sure buddy, it'll just be one of those books that shows you're a normal bloke anyone would want to have a beer with. The kind of bloke people would happily vote for...." a Twitter user wrote.

The book will be in bookstores from August 18.

Publisher Harper Collins lists the book on its website for pre-order for $18.99.