Spousal privilege

[4] Instead, it is rooted in the idea that those who are married should feel safe openly communicating with each other without fear of future litigation or criminal proceedings.

[4] Under U.S. federal common law, the spousal testimonial privilege is held by the witness-spouse, not the party-spouse, and therefore does not prevent a spouse who wishes to testify from doing so.

[5] The rationale of this rule is that if a witness-spouse desires to testify against the party-spouse, there is no marital harmony left to protect through the obstruction of such testimony.

A majority of U.S. jurisdictions, however, do not follow U.S. federal common law; in most states, the party-spouse, and not the witness-spouse, is the holder of spousal testimonial privilege.

It was initially assumed that the Act also meant spouses could be compelled to give such evidence, but the House of Lords ruled otherwise in Leach v R (1912).

[8] However, in Hoskyn v Metropolitan Police Commissioner (1978) the House of Lords overruled Lapworth, ending the personal violence exception, ruling that spouses are competent but not compellable witnesses for the prosecution in all cases, thus restoring the 1912 decision in Leach.

[8] In reaching this view, judges were swayed by the special status of marriage, and the "natural repugnance" that the public would feel at seeing a wife give evidence against her husband in a wide range of scenarios.

[9] This absolute immunity lasted only until the entry into force of section 80 of the Police and Criminal Evidence Act 1984, which restored in limited cases the ability of the prosecution to compel the testimony of the spouse of the accused (later amended to include civil partners), namely where the defendant has been charged with "assault on, or injury or a threat of injury to" the spouse or a child under 16, or a sexual offence toward a child under 16.

[12] However, a spouse (or civil partner) who is an active co-defendant to the charge can only testify for the defence (and cannot be compelled to do so by either side), part of her own right to the privilege against self-incrimination.

Its existence was assumed by late nineteenth century writers, but in 1939 Sir Wilfred Greene, MR, noted in the Court of Appeal in Shenton v Tyler [15] that having researched the subject he found no evidence to support this view[16][17] and that, rather, any such privilege was solely the result of statute.

In particular Sir Wilfred cited, as the sole origin of the privilege, section 3 of the Evidence Amendment Act 1853 which provided that, in civil cases, "no husband shall be compellable to disclose any communication made to him by his wife during the marriage, and no wife shall be compellable to disclose any communication made to her by her husband during the marriage".

A 2019 Court of Appeal ruling found the protection to not testify against one's spouse extends only to married couples and not civil partnerships or other forms of relationships.

However, a form of spousal privilege in criminal trials was for a long time preserved in Australian statute law, by the Evidence Acts.