Vertonghen is entitled to 15 per cent of the agreed £9.5million transfer deal under the terms of his deal with the Dutch champions.
Ajax have indicated their reluctance to honour the clause and, while the 25-year-old still seeks a move to White Hart Lane, he is resigned to staying in Amsterdam.
"This is a shame. I thought that it would be sorted out much sooner," he told Dutch newspaper Algemeen Dagblad. "As it looks now, I'll be at Ajax on July 2. I'm hoping for a solution, but I'm not expecting a solution.
"I have one advantage: Ajax have got a good coach who knows me. I play in a good, stable squad. Let's become champions with Ajax for the third time in a row."
Vertonghen is astonished that specific details of his contract have been released.
"I'm shocked. The percentage is correct - it's unbelievable. I know that at Ajax a lot of things are leaking," he said. "When you hear it about other football players, you don't feel it. It's different when it's about yourself."