Toby Alderweireld has reportedly told Tottenham Hotspur that he will only sign a new contract at the club if a release clause is included.
There were some concerns about the defender's future when reports in Italy claimed that Inter Milan have an interest in him.
Recently it was claimed that the 28-year-old wants a significant wage increase, rising from £50,000 a week to £100,000 a week.
Now, according to The Times, Alderweireld is demanding that a £25.3m buyout clause be included, but the club have so far rejected his request.
It is believed that the North London outfit have the option to extend the defender's contract by one year, but that in turn gives the player the right to add in the clause.
Alderweireld's current deal does not expire until 2019.