QPR manager Harry Redknapp admits preserving QPR's Premier League status is the most daunting challenge of his long career.
Redknapp arrives at Loftus Road after Mark Hughes's sacking last week with his new side bottom of the table and without a win after 13 league matches this season.
The 65-year-old has hauled both Tottenham and Portsmouth away from the relegation zone in the past.
But, speaking at his first press conference as QPR boss on Monday, he conceded the task of lifting the struggling west London team out of the bottom three is the toughest test he has ever faced.
"We mustn't kid ourselves, this is much tougher than those two jobs in my opinion, but I'm optimistic we can pull it off," Redknapp said.
"I want to be successful here, really badly. I want to keep this team in the Premier League.
"If the players try as hard as I am going to try we'll be successful."
Redknapp is back in management after leaving Tottenham under a cloud at the end of last season when he fell out with chairman Daniel Levy and he is determined to make the most of his latest challenge, however testing the circumstances.
After watching QPR's 3-1 defeat at Manchester United on Saturday, Redknapp -- who didn't pick the team for the Old Trafford clash as he was only appointed on the morning of the match -- admitted his players will need to show an improved work ethic and take more responsibility if they want to avoid relegation.
"We've got to do better to give ourselves any chance of getting out of this mess," he said.
"I need 11 people with ability to put effort in. If they don't they're not going to play and I'll get 11 people who do.
I've got no time for people who lose the ball and stand their with hands in the air.
"The lads I met yesterday were all upbeat. They've got to realise they are in this position because they haven't really performed to their capabilities and they've got to do better.
"The players have to take responsibility for performances, they've got to up their performance level and get us out of trouble."
Redknapp has a well-earned reputation as a shrewd operator in the transfer market and he will be making moves to improve the squad during the January window.
And, with strikers Bobby Zamora and Andy Johnson both long-term injury victims, Redknapp admitted he is keen to sign a forward.
"We are not overloaded with strikers here. That's certainly an area we are short in," he said.
Asked about the possibility of signing David Beckham on loan from LA Galaxy, Redknapp, who had been keen to bring the former Manchester United to Tottenham, added: "I got a lovely text from David the other night, just wishing me well here.
"To have him at any football club would be a great influence on the club, but we've not discussed anything."
Getting the best out of QPR's talented but inconsistent playmaker Adel Taarabt will be vital to Redknapp's hopes of staying up and he insisted there would be no clash of personalities with the Moroccan, who was sold by the new QPR boss during his time at Tottenham.
"He wasn't a player I wanted to sell," Redknapp said. "He couldn't get in the team at Tottenham.
"I always felt he had the ability to become a top player. I've got to get the best out of him."
Redknapp also confirmed that Joe Jordan and Kevin Bond, who worked as his coaches at Tottenham, are in the process of agreeing deals to join him at QPR.