Is it permissible for my friend to force his wife into an Islamic divorce, despite her refusal and her request for separation according to English law?

It is not permissible for a woman to seek divorce without a justifiable reason; otherwise, she would expose herself to severe warning, as the Prophet (peace be upon him) said: "Any woman who asks her husband for divorce without a sound reason, the fragrance of Paradise will be forbidden to her." If she dislikes staying with him due to something he does (such as committing abominable acts or severe beating), she has the right to seek divorce and is entitled to all her financial rights. If she dislikes staying with him without a fault on his part, and she fears not being able to obey him, she may seek khul' (divorce by mutual consent) by paying whatever they agree upon for him to separate from her, as Allah Almighty says: "And it is not lawful for you to take back anything of what you have given them, except if both fear that they will not be able to uphold the limits of Allah. But if you fear that they will not uphold the limits of Allah, then there is no blame upon either of them for what she gives to free herself."

It is not permissible to exploit man-made laws that contradict Islamic law to obtain what one does not deserve. The obligation is to rule according to the law of Allah, and whatever is obtained contrary to that is ill-gotten gain and forbidden. It is not permissible to resort to man-made courts except out of necessity when there are no Sharia courts, and what is unjustly awarded to a Muslim is not lawful for him to take. The husband should advise his wife to resort to Islamic law and give her all her rights. If she insists on resorting to man-made laws, he should divorce her according to Islamic law, and if he is wronged and suffers financial loss, he should be patient, and he will be rewarded for that by Allah.