What is the ruling on working in an interest-based bank when there is no permissible alternative for earning a livelihood, and is it permissible to return to such work in a case of necessity?

There is no doubt about the prohibition of usury (riba), dealing with it, and assisting in it. This includes working in a usurious bank. However, necessities permit the forbidden. So, whoever is on the verge of perishing and finds no way to feed themselves and their dependents except by working in a usurious bank, or is in distress and hardship that can only be relieved by it, then it is permissible for them because they are compelled to do so. And if leaving the usurious work before finding a permissible job would lead to a legal necessity, then it is permissible to remain in it and eat from its income to the extent of the necessity until another job is found, while diligently and continuously searching and adhering to the commands of the Sharia (definition) as much as possible.