Ajax defender Jan Vertonghen's lawyer says he's within his right to make the move to Tottenham.

The Sunday Mirror says Vertonghen has ­appointed Dutch sports lawyer Harro Knijff to take Ajax to court over his claim for 15 per cent of any ­transfer fee.

Knijff said: "Jan ­Vertonghen is completely right in his stance against Ajax. There is no way Ajax can interpret this ­differently.

"It is a clear case for me.''

If the deal isn't resolved Vertonghen has threatened to sit out the final year of his contract and join Spurs as a free agent next ­summer.