Jenny Eclair and Dom Joly will go into the I'm A Celebrity... jungle today, according to reports.
The comics are two of the three new contestants TV bosses have lined up amid fears that nutritionist Gillian McKeith could quit, The Sun said.
Landing in Brisbane, Jenny said: "One moment I was in my bath in Camberwell, the next I was at Heathrow. I'm on the reserve bench... I have a horrible feeling I could lose it in minutes. I don't like spiders and snakes."
This Morning's Alison Hammond will also join the camp in the next few days to strengthen the show in case there are more walk-outs.
According to The Sun, Jenny, 50, was given the news late on Sunday to catch a plane from Britain after Gillian, who is under close scrutiny after appearing to faint during Monday's Crate Escape bushtucker trial, appeared increasingly fragile.