What is the ruling on a husband divorcing his wife civilly while maintaining the marital relationship Islamically, in order to be able to marry another woman in a country that prohibits polygyny, and is it permissible for the husband to have conjugal relations with his first wife after this civil divorce?

It is permissible to utter the word of divorce before a judge with the intention of multiplicity, provided that two just witnesses attest to the absence of the intention of divorce. This is called 'istir'a' (seeking attestation). Alternatively, one can use an ambiguous (kinayah) rather than an explicit (sarih) pronouncement, and the wife remains under his marital bond. However, if he utters an explicit divorce and intends for it to take effect, he may reconcile with her before the expiration of her 'iddah, provided it is not the third divorce.