It will be the third time they have tried to sign the Croatian midfielder after having two previous bids of £22 million and £27 million rejected.
An offer of £30 million is now being prepared by the Stamford Bridge club and will be submitted early this week.
Chelsea boss Andre Villas-Boas is refusing to give up on landing the playmaker despite Tottenham insisting he isn’t for sale.
Modric is seen as a vital part of Villas-Boas’ plans as he continues to remodel the dressing room in West London.
Manager Harry Redknapp is keen to retain his services and has insisted that his star player is going nowhere.
“He told Sky Sports: We are not going to sell our best players, the likes of Modric and (Gareth) Bale. We’re looking to sell some fringe players but we have had no takers.”
The 25-year-ol is keen to leave White Hart Lane and believes he has been mistreated claiming agreement was in place to let him leave for a ‘big club’ after he signed a new contract last year.
A transfer request was handed in during pre-season only to be rejected by chairman Daniel Levy who is adamant he will remain at the club.