Former Coronation Street star Julie Goodyear, Spandau Ballet's Martin Kemp and comedian Julian Clary are among the latest housemates to enter the Celebrity Big Brother house.
They were joined by former Loose Woman and chart star Coleen Nolan, an Olympic judo competitor, a Page Three girl and stars of US reality shows.
Also taking part is former EastEnders actress Cheryl Fergison - known to viewers as Heather Trott - and journalist Samantha Brick, who achieved notoriety after writing about how difficult it was to be so "beautiful".
Goodyear became a household name for her many years playing Bet Lynch in the ITV soap and at 70 is by far the oldest contestant in this series. Clary, a regular on Radio 4's Just A Minute and former Strictly Come Dancing star - and Kemp, who has carved out an acting career following his band's split notably playing Steve Owen in EastEnders - are both in their 50s.
Nolan follows her former Loose Women co-star Denise Welch on to the show. Welch appeared in CBB in January, famously appearing topless and drunk but eventually emerging as the winner of the three-week run.
But the show has had a setback with one potential housemate - Duane "Dog" Chapman from US series Dog The Bounty Hunter - was denied a UK visa. The reality TV star was all set to appear but was prevented from doing so because of a 1970s murder conviction.
Channel 5 has increasingly milked the format since it bought the rights to Big Brother and this is the third celebrity version to launch in the space of a year. But the audience for Monday's final of the normal Big Brother series shows it is experiencing diminishing returns. It pulled in an average of just 1.5 million viewers, making it the least viewed finale of a series to date - less than 40% of the audience for the climax of Big Brother in 2010 before it was dropped by Channel 4.
Also taking part are Team GB judo competitor Ashley McKenzie, Mike "the Situation" Sorrentino from US TV show Jersey Shore and former So Solid Crew rapper MC Harvey, formerly married to Britain's Got Talent judge Alesha Dixon.
Glamour model Rhian Sugden, who hit the headlines after exchanging racy text messages with TV host Vernon Kay, is also taking part, along with lads' mag model Danica Thrall and Jasmine Lennard, a finalist in TV's Make Me A Supermodel who claims to have had a fling with Simon Cowell.
Milan-born Prince Lorenzo Borghese, who starred in US series The Bachelor, is also among housemates for the show, which runs for around three weeks.