Nick has a long-standing relationship with Lord Sugar; the pair started working together in 1983 when Nick began promoting Alan's Amstrad brand.
Nick Hewer is leaving The Apprentice after a decade on the show
His exit was announced as he filmed the final of this year's series, which will be screened on Sunday at 9pm. Viewers will see Bianca Miller and Mark Wright fight it out for the chance to win a £250,000 investment for Lord Sugar.
Nick has appeared on The Apprentice since it began in 2005. He and Karren Brady are tasked with keeping an eye on the candidates and giving feedback to Lord Sugar when he decides who to fire each week in the boardroom.
Karren is the second advisor to work alongside Nick in the role, following Margaret Mountford's departure in 2009.
It's with a heavy heart I have to say farewell to my good friend Nick Hewer from the apprentice. I thank him sincerely for the past 10 years— Lord Sugar (@Lord_Sugar) December 18, 2014
Lord Sugar tweeted a response to Nick's announcement
Lord Sugar tweeted his response to Nick's announcement, saying, "It's with a heavy heart I have to say farewell to my good friend Nick Hewer from the apprentice. I thank him sincerely for the past 10 years."
Explaining his departure in a statement, Nick said, "I've been pondering my departure from The Apprentice for a while and have decided that year 10 is the appropriate time.
"So I leave with relief, tinged with regret. Anyone can do what Karren and I have been doing, but it takes stamina to follow the candidates week after week, and my stamina is not up to those long weeks."
Nick Hewer alongside Lord Sugar and Karren Brady
Nick – who hosts the Channel 4 show Countdown – also paid tribute to the show's many candidates.
"I've enjoyed being part of this wonderful television series for two reasons: firstly, because it's been fun and has opened up many unexpected opportunities for me, but more importantly, because I think The Apprentice is a truly valuable programme, teaching young people the basics of business – not in a classroom setting, but in a wonderfully entertaining format.
"And the winners each year validate the value of the show – talented, creative and hardworking young people, all of whom are making a great success of their business."