If one wanted to be a commercial lawyer (in a western country) and would work in a law firm that has clients such as banks that charge riba and engage in haram investments and etc. I would like to ask your opinion on whether this is permissible.
Would it be permissible if they were at the same law firm but did not work in any financial practise areas. What kind of legal work would not be haram in commercial law?
A Muslim lawyer must fight for justice. and against oppression, no matter who the client is. Allah says in the Quran: “Believers! Be upholders of justice, and bearers of witness to truth for the sake of Allah,165 even though it may either be against yourselves or against your parents and kinsmen, or the rich or the poor: for Allah is more concerned with their well-being than you are. Do not, then, follow your own desires lest you keep away from justice. If you twist or turn away from (the truth), know that Allah is well aware of all that you do.” [S4:135]
If the client is a bank, then it depends on the nature of the case. If you are fighting for them to benefit from riba, then you are helping in an unjust cause, which means it would not be permissible to perform such function.
So for me ultimately, being a lawyer is not impermissible in itself. But, it will depends on the each individual cases.