In most jurisdictions, if there is sufficient cause, the employer may terminate the employee without providing notice or pay in lieu of notice. However, the employer must ensure that the reason for termination is properly communicated at the time of dismissal.
Some examples of sufficient cause are dishonesty, disloyalty, insubordination, lateness/absenteeism, disruption of business of affairs, alcohol or drug use, incompetence, neglect of duty, criminal or immoral conduct, and sexual harassment. Note that the employer may ultimately have to prove to a court that there was sufficient cause for termination.