A study claims one in three workers think their job will be automated within the next decade, but many have no been offered new skills to prepare them for changes to work.
Services firm ADP conducted research which also found one in 10 workers believe a robot will take their job by 2020.
Half of the 1,300 workers involved in the survey claimed their employer wasn't preparing to retrain them or offer a chance for them to gain new skills.
It found workers aged under 35 were most likely to believe their job will be replaced by a machine.
The report added jobs in computing and telecoms were most likely to be affected.
Jeff Phipps, managing director of ADP, said: "Automation may seem like an issue for future generations, but our findings show that machines could replace thousands of employees in as few as five years.
"Artificial intelligence and robotics are progressing at such a pace that machines will soon have the capability to do the job of humans in a whole range of professions and industries.
"While this might be good for efficiency and productivity, it could leave thousands facing redundancy and change the face of the workplace forever.
"More robots in the workplace won't mean all humans become obsolete, as new and maybe better jobs will be created, while other roles will change considerably.
"By starting to upskill and retrain workers now, employers can ensure they and their employees are as ready as possible to work side-by-side with the machines."