They call it the "Vampire Theory". The idea that when it comes to the workforce, employers constantly crave the fresh blood of younger workers.
Jack Shirvell, at the age of 81, is still working in aviation
According to a recent study, ageism is the most common form of prejudice in the UK ahead of sexism or racism.
Panorama gained exclusive access to a comprehensive undercover project which reveals remarkable levels of discrimination against a job applicant on the grounds that she is considered too old at the age of 39.
In another case, 54-year-old Glen Penfold discovered he was too old for a post when recruitment consultants trying to find work for him made the classic error of mistakenly emailing the person they were discussing, admitting that Glen would struggle due to "the fact that he is 54".
Until recently one of the most experienced managers in the telecoms industry, Glen has applied for over 150 jobs since September and has landed just one interview.
The programme also features the exceptional story of Jack Shirvell, who at the age of 81 is still working in aviation, training pilots from all over the world in state of the art flight simulator, proving that "old" doesn't automatically mean "decrepit".
This is his 65th year working in aviation - in 1957 he flew Britain's first H Bomb across the Atlantic before it was test bombed near Chrismas Island.
The government believes this "last outpost of discrimination" is costing the country billions of pounds a year in lost productivity and welfare payments.
Much is expected of the new anti-age discrimination laws due to be introduced later this year.
Panorama examines how the legislation will change the way we work, from removing dates of birth from job applications to banning unacceptable ageist banter in the office.
According to James Davies, an employment lawyer, it could represent "the most important change in employment laws since the race and sex discrimination laws of a generation ago".
Panorama: Must Have Own Teeth was on BBC One on Sunday 9 April 2006.