Tottenham Hotspur sacked manager Juande Ramos on Saturday and Portsmouth's Harry Redknapp said he would be taking charge of the English Premier League team.
Speaking to Sky Sports News, Redknapp said he had accepted Tottenham's offer to become manager and Portsmouth would receive about 5 million pounds in compensation.
"It's a big opportunity for me to manage a big club before I retire," said the 61-year-old. "Until yesterday morning when I got the phone call (from Tottenham) I never thought I would ever leave.
"I won't pick the team for Sunday but it will all be sorted out tonight and I'll be there in the morning."
Tottenham, who are four points adrift at the foot of the table, face Bolton Wanderers at home on Sunday before visiting north London rivals Arsenal on Wednesday.
Spurs had said on their website (www.tottenhamhotspur.com) that Ramos, French sporting director Damien Comolli and Uruguayan assistant manager Gus Poyet, had left the club.
It added that Portsmouth had "reluctantly agreed" that Tottenham could hold discussions with Redknapp.
The trio paid the price for the worst start to a league campaign in the north London team's history.
Spurs have just two draws from their opening eight matches and in midweek lost 2-0 at Udinese in the UEFA Cup.
Spaniard Ramos was hired almost exactly a year ago after Tottenham sacked Martin Jol despite the Dutchman guiding the team to two straight fifth place finishes in the league.
Ramos made a good start to his Spurs career, taking them to the League Cup final where they beat Chelsea 2-1, the club's first silverware for nearly a decade.
However, a summer of frenzied transfer activity saw several first-choice players leave, notably Bulgaria striker Dimitar Berbatov to Manchester United and Robbie Keane to Liverpool.
England striker Jermain Defoe was also sold last January to Redknapp's Portsmouth.
Tottenham splashed out about 60 million pounds on the likes of Croatia midfielder Luka Modric, England winger David Bentley, Russia striker Roman Pavlyuchenko and Brazilian goalkeeper Heurelho Gomes.
However, the new faces have not gelled and Spurs have yet to win a league match this season with Darren Bent, fourth choice striker last season, often playing up front alone.
Apart from a 1-1 draw at Chelsea, Tottenham's only other point this season was in a 0-0 home draw with Wigan Athletic.
They lost at home to promoted Hull City and last week were beaten at Stoke City, another side fresh from the Championship (second division), finishing the match with nine men after two sendings off.
Redknapp, who has had spells in charge at West Ham United and Southampton and last season turned down the chance to take over as manager at Newcastle United, faces a tough task turning around Tottenham's season.
"I will go into the dressing room tomorrow and meet the players," he said. "We need to get a result against Bolton. The club is on a horrendous run. There is plenty of talent in the squad but maybe there is something of a soft centre."
Spurs, who have yet to officially confirm Redkanpp's appointment, said reserve team coach Clive Allen would be in charge for Sunday's match at White Hart Lane.
