khula is definately an absolute right. even if the woman lacks the grounds for seeking khula i.e cruelty,impotence,imprisonment,desertion,failure to maintain, lunancy etc, she can seek khula by filing a petition in the court.

"however, it must be remembered that jurisprudence is developed in such a way that bow wife does not have to rely upon these grounds and only thing she has to establish is profound hatred and courts release her from marriage tie"

page 305,muslim law and jurisprudence by aatir rizvi( jahangir success series)