After the sinking of Celebrity Love Island and the turn-off that was Celebrity Wrestling, many could be forgiven for thinking reality TV was dead. But Big Brother is waiting to defy the critics.

George Orwell introduced Big Brother in his novel 1984, but mention the name these days and most people associate it with a reality TV show not a literary invention.

Big Brother returns to C4 - and for the first time on Freeview - next week to show its inferior celebrity imitators who's the daddy of them all (if you'll pardon me mixing up the relatives).

With Celebrity Love Island sinking faster than the Titanic after it hit that iceberg, it can only be a matter of time before ITV1 abandons that venture and leaves the sun, sea and sex seekers to fend for themselves.

Viewers have made it plain that they're not interested, with two million of them deserting the show since Monday's launch. Even that was well beaten by BBC1's drama New Tricks, about pensioner policemen.

Coming so soon after the demise of Celebrity Wrestling and five's The Farm resorting to turkey insemination to keep people watching, you might think the reality TV boom is over.

But the doom and gloom merchants said exactly that about Big Brother after the fourth series in 2003 when a poor selection of housemates led to what was generally considered a pretty boring series.

Last summer's fifth series reversed that with a splendidly dotty array of housemates and, of course, Stu and Michelle's romance - well, the first Big Brother bonk, to be precise.

To top it all, Nadia the excitable, high heel wearing Portuguese trans-sexual totters out of the house as the winner. All very different to the first winner, DIY man Craig Phillips.

What viewers are weary of is not reality TV but the parade of Z-list celebrities clamouring for a career boost. The Big Brother format is still a winner: confine a diverse group of people in an unfamiliar space, light the touch paper and stand clear as the fireworks explode.

Those trying to pass for celebrities don't work any more because we don't care what happens to them. We know what they're going to do - play up to the camera to ensure they get a record contract, magazine deal or new TV show out of the venture.

They're only acting for the cameras, whereas the housemates are, by and large, for real. A few may have an eye on a new career and playing the game to win. Past experience should tell them that most will return to normal life and normal jobs.

Celebrities are too predictable. With housemates, you're never quite sure what they're going to do. Viewers can imagine how they'd react in the same situation. The very first series showed how characters such as Nasty Nick emerge as Big Brother progressed. Gathering together a group of strangers is like going on holiday on a coach tour. C4 realised this and even made a recent series around that very idea called - what else? - Coach Trip.

The pressure is on the makers of Big Brother to up the stakes each time. The 2004 series saw them turn "evil" with lots of nasty surprises to shake up housemates and stop them becoming complacent or think they could outwit Big Brother.

The secret is in the casting. Executive producer Sharon Powers says auditions around the country went "amazingly well" and that the huge turnout of would-be housemates signals the interest in Big Brother is as strong as ever.

"Generally, the best people at auditions stand out, not because they've turned up in outrageous outfits, but because they had something to say for themselves," she explains.

"There is no identikit housemate that we set out to find. When someone has that something extra, whatever that might be, they genuinely stand out from the thousands of applicants.

"The audition process comprises many stages over a few months, which allows us to get to know potential housemates as much as we possibly can. Ultimately we try to choose people who have what it takes to entertain the public all summer."

That's not to say they didn't see some outrageous sights along the way, including "a Scotsman wearing nothing but a ginger wig and a kilt, and lots of girls leaving very little to the imagination."

The house has been redesigned for the sixth series, with plenty of twists and turns in store to keep housemates on their toes. Powers says the house is as small as BB5, even though the feel of it will be completely different. "We want to look aspirational and sumptuous to the viewers, but for the housemates it will soon prove to be uncomfortable and claustrophobic," she says.

They know which housemates viewers like best through a survey on the official Big Brother website. People have been voting for their favourites among the 62 housemates who've been locked up over the past five years.

All will be revealed in two C4 programmes in the run-up to the new series. Powers has her own favourites. "It was a wonderful moment when Nadia won BB5 because it showed how the nation had embraced her emotional journey," she says.

"Personally, one of my favourite moments from last year was when Ahmed staged a military coup and told Big Brother he was 'not a sandwich'.

"Others that spring to mind are Alex and Jonny having a row over people peeing in the shower and, of course, Jade asking, 'Am I a minger?'.

* Big Brother: The Top 20 Housemates is on C4 on Wednesday at 11.40pm and Thursday at 11.35pm.

* Big Brother begins with the live launch show on C4 on Friday at 9pm.

Published: 21/05/2005