Can a manager shiftly stop giving a casual employee shifts altogether?

This may seem a bit odd, but do you know what the laws are in relation to this:

Can a manager simply stop giving an employee shifts altogether? If a manager decides they no longer want the employee to work for them, but does not have any grounds to directly fire them, is this approach acceptable?

Or if the manager wants to reduce the employees time at work, is there a minimum number of shifts every year the employer must give the employee each year?

Any background information on this topic would be great

Unfortunately yes.
Employers are very well versed regarding unfair dismissal laws.{Especially for casual and part-time workers,as there's no worded contract}
I know a girl that when faced with new management[the manager had already secured a replacement to fill her position] was forced to look for alternate employment,as he reduced her hours to a point of being pretty much unemployed anyway.

Source(s):

Sorry if this is what you're going through at the moment.