Tottenham are refusing to allow Jan Vertonghen to leave this month before they have a replacement signed.

The experienced defender is off contract in June and fielding interest from across Europe.

Ajax have been in contact and asked Spurs about Vertonghen's availability this transfer window, but were warned he wouldn't be leaving unless a replacement is found.

De Telegraaf says Ajax chief Marc Overmars has been speaking with Vertonghen for the past week, though the Belgian's personal demands are also working against a deal.

A move to Italy is emerging as a major option for Vertonghen, where Napoli are keen.