The Essex-born singer's odds of victory have only drifted slightly to 4/11 following the revelation this week that he has been leaving the compound for X Factor tour rehearsals.
A spokesperson for Ladbrokes commented: "Rylan's been the favourite since day one and it's hard to see a last-minute upset happening."
More than 60% of the 25,000 voters in Digital Spy's exclusive poll on the scandal said they were angry at Channel 5 for misleading them about Rylan's departures.
Tricia Penrose, who was favourite for the eviction last Friday (January 18) that saw Gillian Taylforth leave the house, is now second favourite to win at 5/2.
Heidi and Spencer Pratt are third with odds of 12/1, even though it has been reported that they will get bodyguards once they leave the house due to the extent of their unpopularity.
Frankie Dettori is favourite with the bookmakers to be evicted in tonight's (January 23) live programme with odds of 7/4. Neighbours actor Ryan Moloney and Penrose are next at 7/2.
"As far as the money's concerned it looks like Frankie's about to fall at the last hurdle," Ladbrokes said.
Celebrity Big Brother continues tonight at 9pm on Channel 5.