The idea is part of a wider programme being considered by the Royal Liverpool University Hospital, which would discriminate against smokers among job applicants and withdraw sickness benefits from those who take time off with smoking or drink-related illnesses.
Managers at the hospital say that the radical proposals are an attempt to formalise existing sanctions over alcohol as well as taking the initiative with regard to the health of staff.
But union officials who were circulated with the discussion document last week were horrified at what they see as an infringement of their members' rights, and promised to fight the move to the bitter end.
Bob Gregory, Merseyside regional officer of the public employees' union Nupe, said he believed the document was a panic measure after the award of pounds 15,000 damages last month to a woman who successfully argued that she had contracted chronic bronchitis through the persistent smoking of colleagues.
He said that smoking was already banned throughout much of the hospital, being allowed only in specially designated areas, a situation to which he and staff had no objection.
The document, which has provoked an outcry in the hospital, plans to go much further, with a total ban and a demand that smokers who apply for jobs must declare their habit on application forms.
The clampdown on alcohol would mean that all staff - doctors, ancillary staff, managers and administrators - would be banned from drinking before coming on shift, during lunch breaks and even at staff parties.
To enforce the ban, which is as much for health reasons as for the safety of staff and patients, managers propose that staff could have to take a breath test. While acknowledging that managers would have no power to force people to take the test, refusal could leave employees open to disciplinary action and dismissal.
Carl Dodd, a spokesman for the hospital, said breath testing would provide managers, who could currently send staff home if they smelt of alcohol, with a more objective examination.
The hospital's operational manager, Tony Lee, said: 'Social attitudes to drink are changing. I think it is proper to ask a person, when they apply for a job, whether he or she smokes, particularly in a health service job.'
He added that the rules on smoking and drinking would also apply to patients and visitors. But Mr Gregory said union officials would meet management this week in an effort to get the plans quashed and come up with some sensible guidelines.
He added: 'I am appalled. The whole idea is preposterous. It should be a matter of freedom of choice whether you smoke or take a drink in moderation during meal breaks. They have to trust the staff.'