Porro is on the books at Sporting Lisbon and Spurs boss Antonio Conte wants him as another option at right wing-back.
Sporting Lisbon are proving difficult however as they continue to insist Tottenham must trigger Porro’s €45m release clause.
While Spurs do not want to do that, they have put an agreement in place with the player in the event they can convince Sporting Lisbon to accept a lower fee.
They have agreed a contract with Porro, according to Italian journalist Nicolo Schira, which will run until the summer of 2027.
Porro appears happy to move to Tottenham and the emphasis is now on the north London side to do a deal with Sporting Lisbon.
The 23-year-old is a regular in the Sporting Lisbon side and losing him mid-season would be a blow for the Portuguese.
They have been urged to sell though by a former club vice-president, who feels Sporting Lisbon need to deal with their financial issues.