Lord Sugar's sidekick Nick Hewer is to leave BBC1 hit series The Apprentice after a decade.

The PR guru, who has worked with the businessman since 1983 when he began promoting the Amstrad brand, has been an adviser on the show since it started in 2005.

Hewer, 70, said he thought it was the "appropriate time" as his stamina is not what it was, but said his departure was with "relief tinged with regret".

He and Karren Brady keep an eye on the hopefuls and give feedback to Lord Sugar when he decides who to fire each week in the boardroom showdown.

His exit was announced as he filmed the final of this year's series, which will be screened on Sunday night at 9pm.

Nick Hewer with Lord Sugar and Karren Brady. Credit: Empics

Hewer, who also hosts Channel 4 afternoon words and numbers game Countdown, questioned the abilities of the show's candidates last month and said they were "not the brightest business brains in Britain".

He said tonight:

I've been pondering my departure from The Apprentice for a while and have decided that year 10 is the appropriate time. Nick Hewer

He added: