Is it permissible to propose to a girl whose marriage has been ruled null and void, but the divorce certificate has not been issued due to her husband's refusal, knowing that I am in a relationship with her?

It is not permissible for a married woman to marry unless her husband divorces her, or a final divorce decree is issued by a judge, and her iddah (definition) (waiting period) from him expires. It is not permissible for a man to propose to her or to establish a relationship with her before that, as all of this is unlawful (haram (definition)). Even if a divorce occurs according to Sharia (definition), she should not marry before the divorce certificate is issued by the court. This is because, outwardly, she is still considered the wife of the first husband, and her marriage to another before her divorce is legally established may subject her to punishment and outwardly give her two husbands.