It is always within your rights to refuse a request for sobriety testing. However, choosing to refuse a breath test, you can be charged with a DUI refusal. (This added offense will be noted on your ticket.)
In Mississippi and Tennessee, law enforcement must obtain a warrant to perform a blood test. This is called a “blood warrant.” To obtain a blood warrant, the arresting officer will need to contact a judge or magistrate and provide probable cause. If the officer has just reason to believe that you are under the influence, the judge or magistrate would then issue a warrant. Once a warrant is issued, you are legally required to submit to a blood test.