The 2,300 employees in Berkshire are angry at having to undergo the tests and fear that failures could cost people wage rises, promotion or even their jobs.
Mars' management said the tests were to 'establish employees' verbal and numerical reasoning'. One of the sample questions was: 'Estimate 24 times 0.8' with five possible answers.
One worker who failed said: 'You need an A-level now just to pack a few Mars bars. It's like asking a monkey to pilot a space ship. They are trying to sort out the wheat from the chaff but a lot of loyal employees will be losing out.'
A 'Stop the Test' leaflet has been circulated among staff at the non-union Mars factory urging protests until the IQ tests are scrapped.
Bob Eagle, Mars' external relations manager, said: 'The tests were not designed to keep people down but to identify the development needs of the people we have.' Fears that jobs were under threat were 'totally unfounded'.Reuse content