Tottenham have been chasing the right-back for much of the transfer window this month, but Sporting Lisbon have proven to be tough negotiators.
Sporting Lisbon started Porro in their Portuguese League Cup final against FC Porto on Saturday evening.
And it has been claimed that the deal is now done, with Porro set to join Tottenham after the final.
However, those suggestions are wide of the mark and Tottenham are still waiting to receive the green light from Sporting Lisbon.
They will hope to be able to push the deal over the line and put Porro at the disposal of Antonio Conte for the remainder of the season.
Losing Porro will be a big blow for Sporting Lisbon, who have been keen to keep hold of him.
The Portuguese giants insisted that Porro would only be able to move on this month if his release clause of €45m was triggered.