The Whites intensified efforts to get a deal over the line for Dieng once they failed with a move to snap up Cody Gakpo from PSV Eindhoven earlier today.
Talks between Leeds and Marseille progressed quickly today over Dieng and both clubs agreed on a €10m fee for him.
The striker was expected to jet to England from France to complete the remaining formalities of a move to Elland Road.
However, Ligue 1 side Nice have made a late move for Dieng and are trying to convince him to stay on France and snub interest from the Whites.
And Dieng is currently at the airport with his private jet on standby as he is weighing up whether to take up Leeds’ offer or to join Nice in the remaining hours of the window.
The Whites are determined to bring in a new striker to their ranks with Rodrigo’s recent injury adding to their need to do so.
Leeds will hope Dieng will opt to leave France and choose to represent the all-white this season in the coming hours.
