You would not necessarily have to leave Canada if you are in an abusive relationship.
Whilst this website is aimed at women, the same principals apply - look at the "abuse by sponsor whilst not yet a PR" section - it says you may be able to make an Humanitarian application.
http://www.owjn.org/owjn_new/index.php?option=com_content&view=article&id=107&Itemid=107
(excuse long post)
Q. If I leave my sponsor how will it affect my immigration status if I am NOT yet a permanent resident?
A. This section applies to women who have inland spousal sponsorship applications in progress. Women in Canada with or without temporary status in Canada can apply from within Canada under the “Spouse or Common law Partner in Canada class.” If you have applied inland for Permanent Residence and are experiencing abuse in your relationship with your spouse or partner sponsor, the following information is important.
If your application for permanent resident status is in progress or you have temporary status, it is best to get legal advice before making any decisions about leaving your partner as you may be at risk of being removed from Canada.
If you have already left your sponsor or need to leave for safety reasons there are remedies available. Citizenship and Immigration Canada does not expect an abused woman to live in danger.
If you decide to leave your partner,
you can pursue an application to remain in Canada on humanitarian and compassionate grounds (“H&C Application”). If you have a removal order made against you, in most cases you can apply for a Pre-Removal Risk Assessment (PRRA) and make an H&C application.4
In any case, you should talk to your own lawyer. It is essential that you obtain independent legal advice because your partner's lawyer must act in the best interest of your partner and you cannot be guaranteed adequate legal representation if you depend on your partner's lawyer.
Q. What is an H&C application?
A. This is the short title for an "Immigration Application Made in Canada on Humanitarian and Compassionate Grounds."
An H&C application is a request to exempt the applicant from the normal requirement of having to make an application for permanent residence from outside of Canada. Abused women can apply to stay in Canada for humanitarian and compassionate grounds. Successful H&C applicants receive Permanent Residence.
Canadian Immigration policies specifically address domestic violence and require immigration officers to be sensitive to women who experience domestic abuse.
To get Permanent Residence based on H&C grounds, applicants must show that there are humanitarian and compassionate considerations relating to their case. Officers must consider the best interests of any children that you have when deciding an H&C application.5 Officers are also required to take into account situations where a woman leaves her spouse or partner because of abuse in H & C applications.6
Your H&C application has to provide details about the abuse, your children, how established you are in Canada and the hardship you would face if you had to return to your country of origin.
If you are thinking about making an H&C application, you should speak with a lawyer. A lawyer can make sure you do not leave out any important information.
An H&C application does not give you any right to stay in Canada while you are waiting for an answer. Once you have made this type of application Immigration may still decide to remove you from Canada -- they do not have to wait for a decision on this application. However, you can apply to Federal Court to stay your removal while you are waiting for a decision on the H&C application.
If you are facing an admissibility hearing, it is essential that you make your H&C application before the hearing as the member at the hearing does not have the power to delay the hearing, nor do they have the power to decide an H&C application.
If immigration approves your application "in principle," you are eligible to apply for a work permit.
http://www.cic.gc.ca/english//resources/manuals/ip/ip05-eng.pdf has details on H & C applications.
Best of luck
thank you for your help, but i have left Canada and i am back in UK. She needs to sort herself out if she wants us to be together. My immigration is still in process and i don't know what to do about it. I am probably going to leave it for now too much stress i cant take it any more.