Forced resignations
Unlike manufacturing companies which usually have a strong trade union to fight for the rights of the worker, there is no union to support the cause of white collar workers in most companies. So the management wishing to sack an employee can just force them to resign.
Though the employee can refuse to resign, most employees submit their “resignation” letter since they are assured that they will receive atleast a part of the benefits due to them. Few employees have sufficient resources at their disposal to fight a large company in court. Also, it is much more difficult to get a job, if you are laid off than it is when you have resigned.