The Institutions of State in the Khilafah by Hizb ut-Tahrir

If the Khalifah lost any of the seven contractual conditions, then he is not legally allowed to continue as a Khalifah, he must be removed. The decision of his removal is solely in the hand of the Mahkamat al-Mazalim, for it is the one that decides whether the Khalifah has lost any of the contracting conditions or not. This is because any matter for which the Khalifah has to be removed, or for which his removal becomes necessary, is known as a ‘Mazlimah’ (an act of injustice) and it should be removed. The matter, however, should be investigated and evidence provided as the ‘mazlima must be proved before a judge. The court of unjust acts (mahkamat al-Mazalim) is the body which rules over any complaints (mudhalim) received, and its judge is the person entitled to prove its occurrence and to decide upon it. Therefore, mahkamat ul-mazalim is the body that decides whether or not the Khalifah lost the contracting conditions, and it is the one who decides the removal of the Khalifah. However, if such a situation did arise and, as a result, the Khalifah stepped down, this would be the end of the matter. If, however, the Muslims thought that he should be removed and the Khalifah disputed with them, the matter would be referred to the judiciary to be settled, for Allah (S.W.T) says: .

"If you dispute about any matter, refer it to Allah and His Messenger" [TMQ 4: 59] .

In other words, if the Ummah disputed with those in authority, this dispute would be between the ruler and the Ummah. Referring the dispute to Allah and the Messenger, means referring it to the judiciary, in other words to the court of unjust acts.