Vertonghen has chosen Spurs ahead of their north London rivals and Harry Redknapp’s team are in advanced negotiations with the Dutch giants over a deal that is likely to be settled at around £8.1 million.
There is even a possibility that Vertonghen will fly to London within the next few days to be shown around Tottenham's new Enfield training headquarters, where they will move permanently in the summer.
It is understood that the defender, who was named Eredivisie player of the year, wants to join Spurs irrespective of whether they play in next season’s Champions League.
“Vertonghen has made his mind up and his move to Spurs could all be agreed within the next few days,” a source told Goal.com.
It will come as a blow to Arsenal, who have been tracking the Belgian centre-back for two years and had earmarked him as one of their primary defensive targets this summer.
But Vertonghen has settled on Spurs because he believes he will be able to play more regularly in his favourite centre-back position for a Champions League calibre club.
The 25-year-old is often pushed out to left-back or central midfield when he plays for the Belgium national team because of the presence of Vincent Kompany and, his friend and former Ajax team-mate, Thomas Vermaelen.
Vertonghen has a year remaining on his Ajax contract and has spoken in recent days of his desire to tie up a move to the Premier League at the start of the transfer window.
Spurs chairman Daniel Levy made a formal move for Vertonghen last week after failing to land him in the January window.
“Tottenham are absolutely my favourite," the defender told De Telegraaf. "Tottenham is a fantastic football club that has the tradition I want. They buy young, eager, offensive-minded players.
“[But] the Ajax board are asking for a very big amount for a player whose contract is running out in year. I trust that both Tottenham and Ajax will put some water in the wine and they will soon reach an agreement.
“I hope that this awareness is there, because a transfer lingering for weeks like Maarten Stekelenburg's [to Roma] seems very harsh.
“He joined at the end of Roma's preparation [for the new season]. I want to be able to blend in with the other players at Spurs from the start [of pre-season training].”