Monaco have specifically accused Manchester City as the only English clubs that have approached Mbappe illegally according to BBC Sport.
The BBC Sport further reported that though City have not commented officially about the issue, but a City source however told BBC Sport that the two clubs have developed a positive relationship over their two Champions League meeting last season.
It is understood that earlier negotiations over the sale of Bernardo Silva to City for £43m this summer were positive, and the ongoing dialogue over £50m-rated full-back Benjamin Mendy has also been cordial.
The source further stated that “They did not believe City had conducted themselves in such a way that would breach the trust that exists between the two clubs”.
Monaco claim clubs have breached regulations of both Fifa and the Ligue de Football Professionnel.
Fifa rules state: “A club intending to conclude a contract with a professional must inform the player’s current club in writing before entering into negotiations with him.”