Nick Hewer to leave The Apprentice

Lord Sugar's adviser on The Apprentice Nick Hewer is to leave the BBC One show after a decade.

The 70-year-old PR expert, who has been on the UK version of the show since it began in 2005, described his decision as "relief tinged with regret".

Hewer started working with Lord Sugar in 1983 when he promoted the Labour peer's Amstrad electronics brand.

His exit was announced as he filmed the final of this year's series, which will be screened on Sunday at 21:00 GMT.

Viewers will see Bianca Miller and Mark Wright fight it out for the chance to win a £250,000 investment from Lord Sugar.

Candidates on The Apprentice compete to go into business with him, with Hewer and fellow adviser Karren Brady keeping an eye on the hopefuls.

At the end of the show they sit alongside Lord Sugar in a boardroom, giving him feedback before he makes his final decision as to who is going to be fired.

Baroness Brady is the second adviser to have worked with Hewer, following Margaret Mountford's departure from The Apprentice in 2009,

Baroness Brady has appeared as Hewer's fellow adviser on the programme since 2009

Lord Sugar tweeted his response to the 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."

Earlier, Hewer himself tweeted: "So farewell Apprentice - it's been 10 yrs of fun working on a worthwhile show but now it's time to file the notebook and throttle back. Bye."

Explaining his decision in a statement, Hewer 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."

He also paid his own tribute to the candidates on the show.

"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 businesses."

Hewer also hosts Channel 4's words and numbers game Countdown.