The White Hart Lane manager faces a difficult task retaining the likes of Luka Modric and Gareth Bale should his side fail to qualify for the Champions League this season.
However, Spurs sit fourth with two games remaining meaning two wins will secure their place in Europe's elite tournament - unless Chelsea triumph in the competition's final against Bayern Munich in May.
“Once you start selling your best players you're finished," Redknapp told reporters.
“I don't know why Tottenham should be seen as a club that will sell its best players. We are not looking to sell our best players. We are looking to build a team here, not dismantle.
“The chairman made a stance with Modric last year - the stance was that we are looking to build, to add to the group we've got and improve for next year, not to go backwards.
“If we go backwards, we're going nowhere basically are we? We will slump back into mid-table mediocrity and we don't want that.”
Modric attracted strong interest from Chelsea last summer and the Blues are rumoured to be considering a return for the Croatian at the end of the season.
Redknapp said: “He's just a fantastic player, a great professional and a top bloke, so you want him here.
“He's right up there with the better players in the world. You can't replace him. You wouldn't be able to replace him with somebody as good.
“That's why the other clubs want to buy him - because he is worth the money. But we don't want to sell him.
“We've got to keep all the best players and add to them if we're going to keep progressing.”
Redknapp’s current contract at White Hart Lane runs out next summer, but the former Southampton man insists he and club chairman Daniel Levy have yet to discuss an extension.
“I have never spoken to anyone about a contract,” the 65-year-old said.
“I have not chased Daniel [Levy], and he doesn't have to chase me. I have a contract here still at the moment so there is no problem.
“I am pleased and privileged to be at a club like Tottenham. They're one of the top clubs in country and in Europe. They're a great club to work for so long may it continue.”
Redknapp had been the bookies favourite for the England job before the FA announced earlier this week that Roy Hodgson would replace Fabio Capello.
But Redknapp offered his full support to the former Liverpool boss and expressed his belief that the Three Lions can succeed in Poland and Ukraine.
“There shouldn't be negativity,” insisted Redknapp. “We have to move on now.
“Roy is in place. We have to get behind him and get behind the team and look forward to the Euros.
“We've got good players in this country, some outstanding footballers so I don't see why we can’t go and have a great tournament.
“We just need to get behind Roy and the team. You will always have your doubters but I'm sure he'll do great and turn those people around.”
Arsenal, sitting third in the Premier League, are just one point ahead of Tottenham and a recent surge in form could allow the Lilywhites to leapfrog their north London rivals.
“Third would be lovely but we have to try to win the last two games and see where we finish,” Redknapp added.