Big Brother returned in the form of a giant hen party last night when producers unveiled an all-female cast in an attempt to revive the tarnished brand.

The show, which accounts for almost one quarter of Channel 4’s annual advertising revenue, was preceded by a humiliating apology over the Shilpa Shetty race row.

The producers want “flirtation” to replace bullying as the theme of the 14-week series. But it was unclear initially how this will be achieved as 11 women trooped into the house. A “hunky” male will reportedly be introduced tomorrow night, with more men replacing the women as the series continues.

All the housemates have signed up to a charter forbidding racist, homophobic or bullying behaviour. One of them, Carole, a former Socialist Workers’ Party activist who campaigns for George Galloway, the Respect MP, is expected to enforce it with rigour.

Producers have selected another Indian-born contestant to follow Shetty, the Bollywood actress. Nicky was born in Bombay and adopted from Mother Teresa’s orphanage in India when she was one year old. But unlike the mild-mannered Shetty, Nicky professes herself to be intolerant and promises to release her “inner bitch”.

Charley Richardson, 21, cousin of the Manchester United football star Kieran Richardson, is unlikely to help housemate harmony. She was questioned by police after two groups of girls attacked each other at a party for the Liverpool player Jermaine Pennant.

Lesley, 60, from Gloucestershire, is the oldest housemate.

The apology before the show was demanded by Ofcom, the media regulator, as a result of serious breaches of the broadcasting code. Police officers will monitor housemates’ behaviour, with a mandate to intervene over suspected racism or violence. Producers have been told to intervene earlier if events spiral out of control.

Yet rows and controversy are key to the show’s popularity. Kevin Lygo, the broadcaster’s director of television, said: “Channel 4 is doing everything possible to prevent a repeat of the public offence caused by the programme.”

Viewing figures and voting have slipped since Big Brother’s peak in 2002. But the series still provided Channel 4 with £150 million of the £664 million it made in advertising revenues last year, according to the media agency Starcom.

Channel 4 has halved the cost of taking part in the eviction process to 25p per call, with 15p spent on administration fees and the rest going to charity. It must repeat the apology on air two more times and it is provide “diversity training” for staff.

Endemol, the series producers, promised a number of “quirky” surprises.

Channel 4 has been accused of relying too heavily on the series, but it argues that, since 2000, Big Brother has become as much a part of the British summer as Wimbledon.

The winners

Whatever happened to . . .

Craig Phillips — 2000 Builder appeared in DIY shows and became comic foil in C4’s Bo’ Selecta!

Brian Dowling — 2001 Irish air steward moved from children’s TV show host to frontman of late-night ITV phone-in quiz

Kate Lawler — 2002 Engagement to footballer Jonathan Woodgate faltered and became international club DJ

Cameron Stout — 2003 Orkney fish trader presented Christian show for BBC and gravitated towards pantomime

Nadia Almada — 2004 Portuguese transsexual admitted herself to clinic for depression when media offers dried up

Anthony Hutton — 2005 Durham hairdresser returned to life in Consett but resurfaced in televised poker competition

Pete Bennett — 2006 Tourette syndrome sufferer launched music career and published autobiography

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