Lyon president Jean-Michel Aulas has confirmed he wants at least 80m from Tottenham for Tanguy Ndombele.
Spurs had reportedly agreed a fee of 60m for the France international.
But Aulas says he wants more from the North London club.
"If I wait another eight days, it will be 80 million," Aulas said on RMC.
"Tottenham made us an opening offer worth 45m. Then, we discussed more. Nothing is done, I can assure you. We are not in a hurry either.
"Tanguy has shown his qualities with the French national team. He is one of our best players. How much is he worth? I do not know, but not just 45m."
He said: "We really need substantial proposals to move forward on Tanguy's future, which will eventually require him to leave.
"We should not say that [there is a deadline], but it's for good reason that we do not need any money until June 30 to present our accounts.
"If he wants to stay, I'll be happy."
