Mrs Macron’s book, called The Liberated Woman, will be published next week.
The book quotes a neighbour from Mr Macron’s home town who claims she typed up the 300-page manuscript.
“Of course, the names were not the same but I think he needed to express what he was feeling at the time.”
A spokeswoman for Emmanuel Macron’s office has declined to comment.
Mr Macron is not the first French politician to attempt to write adult literature.
In 2011, the then French prime minister Édouard Philippe, co-authored Dans l’ombre (In the shadows), which was a political thriller filled with steamy encounters.
French finance minister, Bruno Le Maire, has also written a novel entitled Le Ministre (The Minister), which contains a steamy scene between the minister and his wife in Venice.
Emmanuel Macron did have literary ambitions as a young man.
He wrote at least two unpublished works before he authored a book named Revolution during his election campaign.
Speaking last year to the weekly magazine Le Point, Macron admitted he had not sought a publisher for the earlier works as he “was not happy with them”.
In a separate article for the same magazine, Emmanuel Macron was asked by French author Philippe Besson if he regretted not becoming a writer himself,
Mr Macron replied: “My life isn’t finished yet.”
The French president turned 40 last month.