Tottenham have confirmed the appointment of Harry Redknapp as manager following the sacking of Juande Ramos last night.
The struggling London club have agreed a compensation package of around £5million with Pompey to bring in Redknapp immediately.
Spurs, bottom of the Barclays Premier League, have acted swiftly after axing Ramos, sporting director Damien Comolli and coach Gus Poyet following their disastrous start to the season.
Redknapp admits it was a tough to leave Portsmouth, but believes his move will be best for the long-term future of both clubs.
He told BBC Radio Five Live Sportsweek programme: "I suddenly got a phone call and was told Tottenham were interested in me, and I thought it was a wind-up at first.
"Then when I had spoken to them, I decided it was a good move for everybody, for Portsmouth as well in the long term and they have a terrific compensation deal when things were a bit tight.
"I just thought maybe it was time to move on and Tottenham are a big, big club.
"I thought 'let's just give it a go before it is too late'.
"I could have gone to Newcastle, but did not take it and a lot of people said 'he does not have any ambition', so this is a good chance for me.
"It is a tough job, they are bottom of the league, so let's see what we can do."