The former Tottenham boss laughs off suggestions that the North London club might cancel the Wales international's long-rumored move to Spain.
Reports emerged on Friday morning that the Spurs chief might cancel the proposed world-record transfer following Chelsea's attempt to hijack the North London club's move for Anzhi Makhachkala attacker Willian.
A deal taking the Brazilian to Spurs looked set to be completed on Thursday after the player had passed a medical, but the Blues have moved late. Even so, Redknapp insists that his former club has spent too much this summer to give up the revenue that Bale would bring.
"That's a certainty to happen," Redknapp told TalkSPORT. "Now they've spent all that money there's no way they'll pull the plug on that deal.
"And the boy wants to go. We all know that for a fact."
Tottenham has broken its own transfer record twice this summer during its spending spree to land the likes of Paulinho and Roberto Soldado, and Redknapp believes that Spurs have a squad capable of challenging for the title.
"Tottenham have bought some fantastic players," Redknapp said. "You look at their squad and there is no reason why they can't be challenging to win the league.
"It really is a fantastic squad they have put together."