The right to counsel is guaranteed by section 10(b) of the Canadian Charter of Rights and Freedoms. Upon arrest or detention, every person has the right to retain and instruct counsel without delay and to be informed of that right. The police must also inform the detained person of the availability of duty counsel and Legal Aid.
The right to counsel has two components: the informational component (the police must tell you that you have the right to a lawyer) and the implementational component (the police must give you a reasonable opportunity to actually speak to a lawyer before proceeding with the investigation). The police must hold off on questioning or taking evidence — including breath samples in impaired driving cases — until the accused has had a reasonable opportunity to exercise this right.
Violations of the right to counsel are among the most common grounds for excluding evidence under section 24(2) of the Charter. If the police failed to inform the accused of their right to a lawyer, failed to provide access to a phone, rushed the process, or continued the investigation before the accused spoke to counsel, any evidence obtained may be inadmissible. In impaired driving cases, a right-to-counsel violation can result in the exclusion of breathalyzer results — the Crown's most important evidence.