Follow developments on the Big Brother Blog

Big Brother housemates are in for a £50,000 surprise after producers announced that whoever survives this week’s eviction will be rewarded with a cash prize.

But as is traditional with the Channel 4 reality show, there is a twist. Housemates must first nominate two contestants for eviction without the protection of the diary room walls.

The housemates will be expected to nominate in front of one another and the two with the most votes will face eviction. The contestant who survives will pick up the £50,000 prize.

Whoever secures the cash will still be eligible to scoop the £100,000 winner’s prize when the series draws to an end on Friday, September 5.

The twist comes as contestants Darnell Swallow, Rex Newmark and Mohamed Mohamed face public criticism over their treatment of Australian PA Sara Folino.

The three have been accused of sexism after Wednesday’s night’s programme showed them guessing how many men she had slept with. Darnell went on to call her an “ugly bitch” and said he thought she would have “been around the block”.

Sara told one- time friend Darnell that "I'd rather us not to speak, ever".

Earlier this week Mohamed had told her she could have a cider if she kissed him for 10 seconds. When she refused, he tried to reclaim a cigarette he had earlier given her.

All insisted they were only joking after Sara ended up in tears.

Of the remaining eight contestants, bookmakers say Michael Hughes is the favourite to win the series, followed by Rachel Rice and Lisa Appleton.

Editor's choice

• U2 at Nou Camp Stadium, Barcelona
• The 50 Best Movie Villains
• The 15 golden rules of theatre etiquette