'Tougher' Big Brother 3 launched

Contestants will be watched as they sleep

Channel 4 has launched its third series of reality TV sensation Big Brother - which will feature 12 contestants instead of the usual 10.

New rules will include a "three strikes and you're out" policy for contestants who disobey the disembodied voice of Big Brother.

Contestants must also nominate two of their housemates for eviction each week and give a valid reason for doing so - or be given a warning.

Big Brother is as much part of the British summer as Wimbledon

Peter Grimsdale
Channel 4

But the volunteers' new house - built on a film set at Elstree studios, Hertfordshire - also features a swimming pool for them to relax in.

The programme follows a group of people who live in the same house and are monitored day and night by scores of cameras and microphones.

Each week one housemate is evicted in a public vote - the winner, who gets £70,000, is the last person remaining in the house.

The lucky 12 candidates are still being selected from a shortlist of 50, with organisers refusing to reveal any detail of what the final make-up of the house is likely to be.

There will be daily coverage from the house on Channel 4, with improved live coverage and additional programming on pay-TV service E4.

Summer fixture

Channel 4 recently bought the rights to keep showing Big Brother until at least 2005.

The network's head of cross-platform programming, Peter Grimsdale, told BBC News Online the reality show was now a summer fixture and would not suffer from running alongside the World Cup.

"Big Brother is as much part of the British summer as Wimbledon.

"There are people who are very interested in football and there are people who aren't.

"From the viewers point of view it couldn't have worked out better - the World Cup matches are on in the early morning, and Big Brother will be on Channel 4 in the evenings."

A swimming pool is provided for housemates

Other new features this year will include the ability to vote by text message, and footage from some of the thousands of audition videos will be shown back-to-back on E4 before the show starts.

This year saw a record number of entrants, with 150,000 asking to apply and 10,000 sending audition videos.

The tough regime will see tighter restrictions on what can be taken into the house - musical instruments, games and books will also be banned, but can be earned by completing tasks set by Big Brother.

Instead of being completed during the course of the week, the task will be attempted live on Saturday evenings.

Only one magazine per person will be allowed, along with one suitcase and small bag.

Channel 4 will not confirm a start date for the series, which is due to start later this month.

But the Media Guardian website quotes advertising agencies as saying they have been told it will begin on 28 May.