Portsmouth have confirmed Avram Grant will take over as manager to replace the sacked Paul Hart at Fratton Park.
Hart was dismissed earlier this week following a disappointing start to the season which has left the club bottom of the Premier League.
Grant had been appointed as director of football by Pompey last month and had been awaiting a work permit before starting his role.
He has now received the clearance to start work and will be in charge for Pompey’s home game with champions Manchester United on Saturday.
Pompey chief executive Peter Storrie told the club’s official website: “Avram is a very experienced and respected manager who has managed at the highest level.
“The board believes he is the man to help steer the club out of the relegation zone.
“He knows the club, the players and the set-up at Fratton Park, so it was the logical move to make him the next manager, once the board had decided to relieve Paul Hart of the role.
“He will take charge of training on Friday alongside first-team coaches Paul Groves and Ian Woan.”
Grant had previously been director of football at Portsmouth in 2006-07 before he joined Chelsea in a similar position, later replacing Jose Mourinho as manager. Despite leading Chelsea to runners-up spots in the Premier League and Champions League, he was fired by the London club at the end of the 2007-08 season.