Ten Years Younger star Nicky Hambleton-Jones says she was 'stunned' after discovering she'd been replaced by a younger model.
After five series at the helm of the Channel 4 hit, the network announced last month Miss Hambleton-Jones, 37, will be succeeded by Myleene Klass, who is just 30.
The move has left the host reeling and in a frank new interview she admits it was a 'bitter pill to swallow'.
She also brands Myleene, who co-presents Miss Naked Beauty with Gok Wan, unsuitable for the job, claiming she was only selected because of her youthful good looks.
Nicky told this week's Grazia magazine: 'When I heard that I'd been replaced by Myleene, it was a slap in the face.'
'Perhaps naively, I thought there was a divide in TV between women who are there for their looks and women who are there for their expertise.'
Nicky, who describes herself as a nutritionist, stylist and anti-ageing expert, says: 'I trade on my experience and knowledge, not my looks.
'It does seem to me like a classic case of replacing any women over 35, regardless of how suitable she is for the role, with a younger face.
'For the first time, I felt old and past it.'
Nicky fears women over 35 are an endangered species on television, citing GMTV host Fiona Phillips, 47, and Countdown star Carol Vorderman, 47, who both been replaced by younger women in recent weeks.
She continues: 'I can't let this pass without comment. If 37 is considered too old for telly, where are we headed?'
Channel 4 insists it was Nicky who decided leave the show.
A spokesperson for the network said: 'Myleene is an ideal replacement. Age played absolutely no part in the decision.'
The new series, which starts in the autumn, will be called 10 Years Younger: The Challenge.
The format has also been overhauled - two volunteers will be pitched against one another, one having cosmetic surgery and the other using more natural methods to beat ageing.
A defiant Nicky has now launched her own styling business and claims she has TV projects 'in the pipeline'.
She says: 'I've got no intention of quietly slopping off to knit myself some slippers.'