The Canadian government does has authority to revoke your Pardon if you are convicted of a criminal offence AFTER your Pardon is granted. Depending on the new offence, you might be eligible to reapply after a wait period.
Obtaining a Pardon in Canada is a mutual commitment you are making to the government not to re-offend going forward in your life. Take that seriously. Call 866-383-9744 to get started on your Pardon today.