Modric has been linked with a £25 million move to Manchester United following a successful campaign with Spurs, helping them qualify for the Champions League.
Redknapp is looking to challenge at the top of the Premier league and in Europe next term, and is therefore not interested in allowing one of his most influential players to depart White Hart Lane this summer.
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He said in The Sun: “There's no chance of it happening at all. Luka's key to everything that's happening at this place.
“Everybody knows what I think of him. And if you want to move on to higher levels you don't start flogging off your best players - to anyone.
"I have an excellent squad and - I stress - Luka Modric is going to remain a part of it."
Redknapp is determined not to lose another of his stars to United following the departures of Michael Carrick and Dimitar Berbatov to the Red Devils in recent seasons.
It has been suggested that Spurs are also interested in Manchester City's Stephen Ireland and Bolton defender Gary Cahill, but Redknapp denied the reports.
The club has also been linked with a move for Aston Villa defender Curtis Davies after Martin O'Neill claimed he is open to talks over the 25-year-olds future.
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