Spurs have today announced an initial loan deal to sign the Spanish full-back from Sporting CP, in their second signing of the January transfer window.
The move includes an obligation to purchase Porro on a permanent transfer for a reported £39million in the summer.
Weeks of negotiations looked to have collapsed over the weekend but Spurs reached a breakthrough after the 23-year-old made his final appearance in his former team’s Allianz Cup final defeat to Porto on Saturday.
Porro appared to have missed out on the move before his new club committed to waiving a portion of Marcus Edwards’ sell-on fee, allowing them to complete the signing.
The wing-back will take the No23 shirt in north London.
The deal follows Djed Spence’s move to Rennes on deadline day, on loan until the end of the season.
Fellow right-back Matt Doherty also left the club, mutually agreeing to terminate his contract before signing for Atletico Madrid.
