Critics believe it has an outdated view of business, linking success with being nasty, disloyal, greedy and selfish. The chat-show host Michael Parkinson said it was, "full of vulgar loud people who, for all the wrong reasons, are dobbing each other in".
Its defenders say it has helped to make a spirit of enterprise sexy again, bringing big business into millions of living rooms. The Apprentice has become the thinking person's reality show. Viewers who turn up their noses at Big Brother and its trashy siblings will clear their diaries to turn it on.
With the ostentatiously gruff Alan Sugar responsible for hiring and firing candidates who aspire to work for him, The Apprentice is expected to win huge audiences again for its fourth series, which begins tonight.
There will be a particular Irish interest in the series this year. Following on from the success of Kristina Grimes, the Wicklow woman who finished runner-up last year, Dubliner Jennifer Maguire is expected to vie for Alan Sugar's attention with the sort of shameless immodesty that has become a hallmark of the series.
The marketing consultant, who moved from Ireland to Bristol after her Leaving Cert, boasts: "I can sell pieces of paper for £50. I rate myself as the best salesperson in Europe.''
Jennifer has already overcome difficult hurdles just to get into the series, having been chosen from 20,000 candidates.
Jennifer says she is from a large, feisty family. She has already enjoyed success as a champion showjumper when she was 14. Describing herself as an "iron fist in a velvet glove", she currently works in advertising for the fashion and leisure industries and says she was promoted within two weeks of starting her current job.
"I am a success, totally,'' says the aspiring Apprentice, apparently without a hint of irony.
"I had no training. I started selling on the street. Yet when I ran an office I made £60k in the first six months.''
Jennifer says she applied for The Apprentice because she wanted to throw herself into a challenge. She once worked as a waitress in New York and despite being the "worst waitress in the world" she says her Irish charm got her $250 in tips each night.
It will take a lot more than Irish charm to sweeten the notorious sour-puss Alan Sugar, who has become a TV star with his loud put-downs. A typical dismissal notice is along the lines of, "You're a lightweight! You're fired!''
The new series of The Apprentice sees 16 contestants take on a variety of tasks, including selling coffee from a stall and designing pet accessories.
At the end of each week, they gather before Sugar in the boardroom for one of them to be "fired".
The winning candidate will get to work in one of Sugar's companies for €130,000 a year.
One of the lingering mysteries of the series is why any intelligent young entrepreneur would want to work for Sugar, who appears to delight in insulting the candidates.
Part of the attraction of the series is watching the bright, and not-so-bright, young business brains being humiliated.
It is easy to forget that The Apprentice, like any other reality show, is ultimately about showbusiness, with the emphasis on the 'show' rather than the 'business'. Libby Purves of the London Times described it as "a mercantile panto with Sir Alan Sugar playing his heart out as the Demon King''.
Ultimately, one suspects, the ambition of many of the candidates is to work in television. Since she finished runner-up in the first series in 2005, Saira Khan has gone on to present her own BBC series. Ruth Badger, another failed candidate, is also a regular on television. Other losing candidates have also carved out TV careers.
Like nearly all reality shows, The Apprentice is often not as real as it seems.
'Alan's boardroom', where the performances of contestants are scrutinised, is not actually his real boardroom, but a set built in a TV studio in west London.
And the receptionist Jenny, who calls the candidates in, is not Sugar's real secretary. The role is played by an actress.
At the end of each programme, one candidate is eliminated and is filmed walking away, usually in a disgruntled state, pulling a suitcase. All these exit sequences are actually shot at the start of the series before the outcomes are known.
Even the angry image of Alan Sugar himself may be a l ittle bit contrived. In the run up to the new series Sugar accused the BBC of portraying him as Mr Nasty.
He said he frequently rowed with producers because footage of him being humorous or friendly ended up on the cutting room floor.
"Like it or not, and I don't like it that much, there's a perception of me just banging the table and shouting," he says.
He insists that he has actually sacked very few people during his career.
Last year, contestants were frequently shown to be in tears, apparently quaking in fear of Sugar.
Rory Laing, dismissed by Sugar during last year's series, backs up his old adversary's claims that he was not as nasty as he was painted.
"He is portrayed as a nasty man but he is actually alright and quite amusing in the boardroom," says Laing.
He says Alan Sugar was simply a "figurehead" of the show, whom the contestants rarely saw, but when he did appear to inspect their work, he was "charming".
"There were a couple of times that I saw him," he says. "He was always very pleasant to everyone and would tease one or two people to put us at ease."
As well as Jennifer Maguire, this year's line-up includes a BBC radio sports presenter, a woman who claims to be descended from royalty and an IT expert who won a pay-out after suing her City law firm.
Each will probably be competing to be seen as more brash, loud and gutsy than the next.
The Apprentice starts tonight on BBC 1 at 9pm
What you didn't know about The Apprentice
- The series is modelled on the US programme of the same name, which stars property magnate Donald Trump.
- Alan Sugar's notice of dismissal, "You're Fired'', has become his catchphrase.
But he says he has sacked very few people in his career. He gives the fee for the programme to charity.
- Nick Hewer, Alan Sugar's urbane sidekick in the series, was educated at Clongowes Wood College in Co Kildare. He worked for many years as Sugar's PR man.
- Irish woman Kristina Grimes, last year's runner-up, spurned a job offer from Sugar. She is currently sales director for a property company.
- With a fortune now estimated at over €1 billion, Alan Sugar began by selling electrical goods out of a van.
- Last year's winner, Simon Ambrose, now works for one of Alan Sugar's companies and helped to create one of his property websites.
- Sugar is also familiar to football fans, as he was chairman of Tottenham Hotspur from 1991 to 2001. In June 1991, he and Terry Venables teamed up to buy the club, in the process defeating a bid from publishing tycoon Robert Maxwell.