Discussions were moving towards a positive end over the last few days and Tottenham were growing increasingly confident of landing their top January target.
The 23-year-old right-back was set to join Tottenham and terms were agreed upon between the two clubs for the move.
He was told that he would be allowed to leave after Sunday’s Portuguese League Cup final but that has changed.
It has been claimed that the move is now off and Porro will spend at least the rest of the season at Sporting Lisbon.
Spurs have called off their pursuit of the player after Sporting Lisbon reneged on the terms they have already agreed upon.
Porro has been left distraught after the move was called off but will now continue at Sporting Lisbon.
He has been a regular presence in Ruben Amorim’s side this season and has recorded three goals and eleven assists in 25 matches.
It remains to be seen whether Tottenham look to bring in another full-back before Tuesday’s deadline.
