Penny is the bookies' favourite to be the first housemate to be evicted from Big Brother.
She caused controversy earlier this week by kissing housemate Paul and being seen naked on the show.
Dean is the current favourite to win the show.
Penny's odds of being the first evictee, with online betting firm Blue Square, are 11/10.
Narinder, the first Asian contestant on the show, is second favourite at 9/2.
Warehouse worker Bubble, who admitted he once had a £500-a-week cocaine habit, is at 5/1.
Dean's odds on winning are 4/1.
Elizabeth, Amma, Helen, Brian and Bubble all have odds of 6/1.
Outsider is Penny at 14/1.
The Big Brother housemates are in for a shock when they find out that the first nominations for eviction will take place on Friday.
The ten contestants had originally been told that they had until Monday to decide who they want booted out.
But the show's producers decided to spring a surprise on them and now they will have 24 hours to make their nominations.