Well, here is my proposal for how polygamous marriage should work in Australia:
1) Multiple concurrent legal marriages should be treated in exactly the same way that Australian law currently treats multiple concurrent de facto relationships
2) If you are married under Australian law (and that marriage is legally undissolved), you will be able to concurrently validly marry a subsequent person, provided that (a) you have the written consent of all the people to whom you already have undissolved marriages (b) the person you are marrying has seen those written consents and acknowledges in writing having seen them
3) Foreign polygamous legal marriages will be legally recognised as marriages in Australia (provided they meet all the other legal requirements, like consent, not being incestuous, minimum age requirements, etc); however, if the foreign legal system does not impose consent to polygamy requirements equivalent to (2) above, and an existing spouse did not consent (or a new spouse was unaware of the polygamous nature of the marriage), then they will have the right to void the marriage. (This would represent a reintroduction into the Australian legal system of the concept of a "voidable marriage" – that concept used to exist in Australian law until 1975; it was inherited from English law, and still exists in English law until this day.)
Is there any problem with the above proposal? What is it missing? I think most of the meat is actually in (1); the only non-obvious element in (2) is requiring informed consent from both the existing spouse(s) and the new spouse for a polygamous marriage. Multiple concurrent de facto relationships don't require such informed consent – a man with a legal wife can have a concurrent de facto girlfriend, and keep the wife and the girlfriend secret from each other – that's morally quite reprehensible, but doesn't make the de facto relationship legally any less a valid de facto relationship. I think morally, legally recognised polygamy shouldn't be possible without informed consent of everyone involved; and politically, it would be impossible to legalise it without giving such a guarantee.
The complexity in (3) is how to deal with the fact that some foreign legal systems allow polygamy without knowledge and/or consent – for example, some Islamic countries allow a man to take a second wife without his first wife's permission. I think the best solution, is if a person did not consent to a foreign polygamous marriage, they have the right to annul it under Australian law (but, if they are happy/accepting of it, they don't have to use that right, and it can remain valid.) I wouldn’t make it automatically invalid, because there may be cases where everyone involved knew about and consented to the polygamy, even if that consent wasn’t legally required under that foreign country’s laws, but the lack of a formal requirement for consent means there are no written records to prove it exists even when it actually does
1) Multiple concurrent legal marriages should be treated in exactly the same way that Australian law currently treats multiple concurrent de facto relationships
2) If you are married under Australian law (and that marriage is legally undissolved), you will be able to concurrently validly marry a subsequent person, provided that (a) you have the written consent of all the people to whom you already have undissolved marriages (b) the person you are marrying has seen those written consents and acknowledges in writing having seen them
3) Foreign polygamous legal marriages will be legally recognised as marriages in Australia (provided they meet all the other legal requirements, like consent, not being incestuous, minimum age requirements, etc); however, if the foreign legal system does not impose consent to polygamy requirements equivalent to (2) above, and an existing spouse did not consent (or a new spouse was unaware of the polygamous nature of the marriage), then they will have the right to void the marriage. (This would represent a reintroduction into the Australian legal system of the concept of a "voidable marriage" – that concept used to exist in Australian law until 1975; it was inherited from English law, and still exists in English law until this day.)
Is there any problem with the above proposal? What is it missing? I think most of the meat is actually in (1); the only non-obvious element in (2) is requiring informed consent from both the existing spouse(s) and the new spouse for a polygamous marriage. Multiple concurrent de facto relationships don't require such informed consent – a man with a legal wife can have a concurrent de facto girlfriend, and keep the wife and the girlfriend secret from each other – that's morally quite reprehensible, but doesn't make the de facto relationship legally any less a valid de facto relationship. I think morally, legally recognised polygamy shouldn't be possible without informed consent of everyone involved; and politically, it would be impossible to legalise it without giving such a guarantee.
The complexity in (3) is how to deal with the fact that some foreign legal systems allow polygamy without knowledge and/or consent – for example, some Islamic countries allow a man to take a second wife without his first wife's permission. I think the best solution, is if a person did not consent to a foreign polygamous marriage, they have the right to annul it under Australian law (but, if they are happy/accepting of it, they don't have to use that right, and it can remain valid.) I wouldn’t make it automatically invalid, because there may be cases where everyone involved knew about and consented to the polygamy, even if that consent wasn’t legally required under that foreign country’s laws, but the lack of a formal requirement for consent means there are no written records to prove it exists even when it actually does