Two years ago.....Canada was short of workers and to obtain an LMO, especially in certain Provinces, was reasonably easy.
Unfortunately, the World recession became a reality and Canada, along with most Western Countries, found that the unemployment of Canadian Citizens and PR's increased dramatically. Thus, although LMO's are still being issued, it is by far harder to obtain a positive one at this moment.
You may well have been doing the job for two years, but as PMM stated on another thread about LMO's, your employer should have, in the two years you were working, employed and trained a citizen or PR for the job.
Unless the skill level of your job is high and there is a National shortage of workers in your job expertise, there is a very good chance that a new LMO will not be issued. Make sure your employer advertises both locally and Nationally. Make sure the adverts are paid adverts to prove the Employer is serious about finding a Canadian for the job. Make sure your employer also gives a deatailed explanation about why they havn't employed a Canadian and trained them to do the job during the two years you have been working temporary for them.
I know this sounds like a lot of work, but your employer really has to prove conclusively that there is no alternative but to hire you.
Good luck.