At common law a spouse of an accused is incompetent to testify except where the charge involves the person, liberty, or health, of the spouse.
Section 4(2) of the Canada Evidence Act overturns the common law by stating that:
Spouse of accused
(2) No person is incompetent, or uncompellable, to testify for the prosecution by reason only that they are married to the accused.
Communications during marriage
(3) No husband is compellable to disclose any communication made to him by his wife during their marriage, and no wife is compellable to disclose any communication made to her by her husband during their marriage.
[(4) to (6)]...
R.S., 1985, c. C-5, s. 4; R.S., 1985, c. 19 (3rd Supp.), s. 17; 2002, c. 1, s. 166; 2014, c. 25, s. 34, c. 31, s. 27; 2015, c. 13, s. 52.
There remains however an immunity in relation to "any communication" between the two "during their marriage".
- R v Hawkins, 1996 CanLII 154 (SCC),  3 SCR 1043
Pre-July 2015 Legislation
On July 23, 2015, the Victims Bill of Rights came into force, amending the provisions of the Evidence Act on spousal privilege and immunity.
Prior to the amendments, s. 4(2), (4), and (5) stated:
Accused and spouse
(2) The wife or husband of a person charged with an offence under subsection 136(1) of the Youth Criminal Justice Act or with an offence under any of sections 151, 152, 153, 155 or 159, subsection 160(2) or (3), or sections 170 to 173, 179, 215, 218, 271 to 273, 279.01 to 279.03, 280 to 283, 286.1 to 286.3, 291 to 294 or 329 of the Criminal Code, or an attempt to commit any such offence, is a competent and compellable witness for the prosecution without the consent of the person charged.
Offences against young persons
(4) The wife or husband of a person charged with an offence against any of sections 220, 221, 235, 236, 237, 239, 240, 266, 267, 268 or 269 of the Criminal Code where the complainant or victim is under the age of fourteen years is a competent and compellable witness for the prosecution without the consent of the person charged.
(5) Nothing in this section affects a case where the wife or husband of a person charged with an offence may at common law be called as a witness without the consent of that person.
The Canada Evidence Act has added exceptions allowing the spouse to be competent and compellable for the Crown and co-accused:
- when called by the defence spouse (s 4(1) CEA)
- when the accused is charged with a listed offence which implicate the health and security of the spouse(s 4(2) CEA)
- when the accused is charged with a listed offence and the victim is under the age of 14 (s 4(4) CEA)
- the accused is charged with an offence involving danger to the spouse's "person, liberty, or health", b) when the accused threatened to the spouse's "person, liberty, or health", or c) violence, cruelty or threats are made against the spouse's child. (s 4(5) and the common law)
Offences listed under s. 4(2) consist of:
- Induces, interferes, etc with a young person subject to the YCJA (136)
- Sexual Interference (Offence) (151)
- Invitation to Sexual Touching (Offence) (152)
- Sexual Exploitation (Offence) (153)
- Incest (Offence) (155)
- Anal Intercourse (159)
- Compelling Bestiality or Committing in Front of a Child (160(2),(3))
- Parent or Guardian Procuring Sexual Activities (170)
- Householder permitting sexual activity (171)
- Making sexually explicit materials available to children (171.1)
- Corrupting children (172)
- Child Luring (Offence) (172.1)
- Agree or Arrange a Sexual Offence Against a Child (172.2)
- Indecent Act (Offence) (173)
- Vagrancy (179)
- Abandoning Child (Offence) (218)
- Sexual Assault (Offence) (271)
- Sexual Assault with a Weapon (272)
- Sexual Assault Causing Bodily Harm (272)
- Aggravated Sexual Assault (Offence) (273)
- Trafficking in Persons (Offence) (279.01 to 279.03)
- Abduction of a Young Person (Offence) (280 to 283)
- Commodification of Sexual Services (Offence) (286.1 to 286.3)
- Bigamy (291)
- Procuring a Feigning Marriage (292)
- Polygamy (293)
- Pretending to Solemnize a Marriage (294)
Thus, generally speaking spouse cannot testify on behalf of a co-accused or the crown. In civil trials, provincial evidence acts have removed these presumption, allowing spouses to testify in all circumstances.
The immunity is concern with the state of the relationship at the time of the evidence being given, and not at the time of the incident.
The protection is only only those in a "valid and subsisting" marriage. Thus, the spousal exception does not survived the marriage. "Irreconcilably separated" spouses are not protected where there is no marital harmony to preserve. Thus, spouses with "no reasonable prospect of reconciliation" is exempt from spousal immunity. This is determined objectively and on the balance of probabilities..
A spouse refers only to legally married spouses. Those who are:
- common law,
- separated short of divorce with no hope of reconciliation,
are not subject to the spousal immunity.
However, there is some authority suggesting that s. 4(1) and 4(3) must be read up to include common law partners anywhere there is reference to "husband" or "wife".
A competent spouse for a party is necessarily a compellable witness.
A wife who previously consented to a wiretap of conversations between her and her husband but then refuses to testify at trial may rely on spousal privilege s. 4(3) of the Evidence Act.
- see http://news.gc.ca/web/article-en.do?nid=1006529
- R v Hawkins
- see R v MacPherson (1980) 52 CCC (2d) 547 (NSCA)(*no link)
R v Czipps, 1979 CanLII 2095 (ON CA), (1979) 48 CCC (2d) 166 (ONCA)
R v Sillars (1978) 45 CCC (2d) 283 (BCCA)(*no link)
- R v Schell, 2004 ABCA 143 (CanLII)
- R v Lonsdale, 1973 ALTASCAD 125 (CanLII), (1973) 15 CCC (2d) 201
- R v Salituro, 1991 CanLII 17 (SCC),  3 SCR 654
- R v Jeffrey, 1993 ABCA 245 (CanLII), (1993) 84 CCC (3d) 31 (ABCA)
- R v Martin, 2009 SKCA 37 (CanLII) This rule was found constitutional at R v Thompson (1994) 90 CCC (3d) 519 (ABCA)
- R v Masterson, 2009 CanLII 36305 (ON SC)
R v McGuinty, 1986 CanLII 116 (YK CA), (1986) 27 CCC (3d) 36 (YTCA)
This however is not necessary consistent with UK common law
- R v Zylsatra, 1995 CanLII 893 (ON CA), (1995) 99 CCC (3d) 477
- R v St. Jean (1974) 32 CCC (2d) 438(QCCA)(*no link)
- R v St. Denis, 2010 ONSC 1225 (CanLII)
Spousal privilege is a class protection of certain communications between husband and wife. It is a protection that is separate and apart from spousal competency.
A spouse who is found to be competent and compellable may still invoke privilege to protect their communications.
This class of privilege does not exist at common law, but rather was created by way of s. 4(3) of the Evidence Act, which states:
4 (3) No husband is compellable to disclose any communication made to him by his wife during their marriage, and no wife is compellable to disclose any communication made to her by her husband during their marriage.
Third parties may "testify to communications between husband and wife that were overheard, intercepted, or otherwise discovered".