During the group's lockdown in the bedroom, the Welsh minister admitted that the sound of work being carried out in the rest of the house for tonight's big send-off had started to make him nervous.
"In some respects you'd have been better off going out before the final week," he told the other finalists. "It's pretty crazy, squeaky bum time."
David then revealed his prediction for the outcome of the public vote, telling JJ: "You could win it tonight. You got all those young girlies out there texting like mad.
"I think I'm here among four people who have got a really good chance of winning," he continued, before confirming that he believed JJ and Josie would be the final two.
"I don't think that at all," JJ replied. "I'd love to [win] but it's not gonna happen, so the sooner I get that thought out my head the sooner I can get out there and celebrate Josie winning."
However, Josie was just as adamant that she would come up short in tonight's finale.
"The sooner I get that thought of my head the sooner I can get out there and smooth John James right over," she said.
Josie remains the firm favourite to win Big Brother 11 and secure a place in Ultimate Big Brother, with David her closet competition with odds of 10/1. Meanwhile, JJ is a longshot outsider at 50/1.