Employers are "on shaky legal ground" if they ban staff who refuse to get a Covid-19 vaccine from the workplace, it has been warned.
Employment law expert Alan Hickey said there is currently no legal basis for mandatory vaccination policies.
He said a company could face a discrimination claim if a worker was sanctioned for refusing to get a vaccine and told not to come into the office or dismissed.
He said it is an issue that is likely to be a big concern for employers - particularly in the health service and nursing homes - when the first Covid-19 vaccines become available.
Numerous vaccines are still being developed and are likely to be ready later this year or early next year.
"As matters stand, our view is that employers would be on shaky ground if they seek to make vaccination a condition of employment," said Mr Hickey, services and operations director at employment law consultancy, Peninsula Ireland.
"The decision to take a vaccine will ultimately be a personal one for the employee to make and in the absence of a specific law dealing with the Covid-19 vaccine, employers don't appear to have any legal basis to adopt a mandatory vaccination policy."
He said Irish citizens enjoy a broad set of personal rights that are protected by the Constitution and European charters and conventions.
Employees may not want to have a vaccine for many reasons. They may have been advised not to due to a pre-existing condition or because it could have a negative impact on their mental health.
Workers could also object because of their religious benefits or due to concerns about side effects or the speed at which vaccines have been developed.
He noted that protests by anti-mask and anti-vaccination activists were becoming more and more common.
Mr Hickey said although the Government recommends various vaccination programmes, none is compulsory.
"There is also no evidence to suggest that the Government is going to implement a blanket instruction for every person in Ireland to have the vaccine."
He added that a government-mandated instruction would give employers a stronger legal basis to have a vaccination requirement.
Employers in some sectors may seek agreement with existing staff to have the vaccine or require newly hired workers to get one. However, he said it has not been confirmed whether any sector is considering this.
Mr Hickey said employers in sectors that do not involve caring for vulnerable people, such as in offices or retail outlets, will find it more difficult to try to introduce a restriction.
When asked if the HSE will require staff to get a vaccine if it becomes available, a spokesperson indicated this has not been decided, saying the Department of Health sets policy.
"The Immunisation Strategy Group is currently working on a Covid-19 vaccination programme which the HSE is planning for and will implement in due course," said a HSE statement.
"Priority groups will be determined by the Government based on expert advice."
Meanwhile, Mr Hickey noted workers are not legally obliged to inform their employer if they have Covid-19.
However, he said disciplinary action might be taken as it could be seen as gross misconduct if they "rock into work" with it.