Lyon president Jean-Michel Aulas has confirmed the club have rejected a €45 million (£40m/$51m) bid for Tanguy Ndombele from Tottenham.
The Champions League runners-up are the favourites to land the 22-year-old midfielder but they have fallen short of Lyon's asking price.
The French club have already seen Ferland Mendy leave to join Real Madrid for €48 million (£42.7m/$54m) this summer and Aulas insists they do not need to sell any more players because they are financially secure.
And the president has urged Tottenham to increase their initial offer for the France international if they want to land him in the current transfer window, suggesting they will have to offer close to €80 million (£72m/$101m) to convince Lyon to sell.
"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."
Earlier this week, Aulas said that he would be happy if Ndombele were to stay for at least another season, but says there are many teams eyeing him up this summer.
“Tanguy Ndombele is pragmatic, he did not say: 'tomorrow I'm definitely leaving'," Aulas said on Tuesday. "He has been followed by the big clubs and when they come in [for your players], you have to listen.”He added: “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.”
Ndombele joined Lyon from Amiens in an initial loan deal that was made permanent in July 2018. He has made 96 appearances for the club in all competitions, scoring four goals.