I was employed on a permanent full time basis in September 2001 and in 2009 became a permanent part time employee working 72 hours per fortnight. I have given notice of resignation in writing with 2 weeks notice but my employer insists I have to give 4 weeks notice under the NES. Another employee who was employed on a permanent part time basis in 2001 also resigned 2 months and they accepted her 2 weeks notice. My employer told me this was at the employers discretion. Do I have to give 4 weeks notice or as I changed from full time to part time 4 years ago, do I have to give only 3?