The Croatian was a £40m transfer target for Chelsea last summer and confessed his desire to join the Blues, but was denied his move by Spurs chairman Daniel Levy.
However, Spurs are once again planning a stubborn stance and will attempt to persuade the midfielder with a £100,000-a-week contract.
Boss Harry Redknapp revealed: "I don't know where we are at with Luka. I'm sure the club is looking to tie him up."
Modric has made 37 appearances for the Lilywhites this season, scoring four goals.