Abstract

Collusion between a lawyer and the opposing party, as a clear instance of conflict of interest, is one of the fundamental challenges in the legal and jurisprudential system that violates the client's rights and undermines public trust in the institution of advocacy. This research aims to safeguard the legal profession against this phenomenon, with an emphasis on analyzing the responsibility and enforcement guarantees governing it. By referencing ethical and legal principles in Islamic jurisprudence, Iranian statutory laws, the binding precedents of the Supreme Court, and the opinions of legal scholars, this study demonstrates that avoiding collusion and conflicts of interest is a fundamental requirement of the attorney-client relationship, rooted in the principle of trustworthiness, the principle of good faith, and the rule of no harm (Lā Ḍarar). An examination of the views of prominent Shia jurists, including Imam Khomeini, Makarem Shirazi, Muhaqqiq al-Hilli, Allamah al-Hilli, Shahid al-Thani, Shaykh al-Tusi, Muhaqqiq al-Ardabili, Sayyid Muhsin al-Hakim, Sayyid Ali al-Sistani, Muhammad Jawad Mughniyah, Muhammad Taqi al-Modarresi, Muhammad Fazil Muwahhidi Lankarani, Muhammad Jawad Fazil Lankarani, Sayyid Muhammad Kazim Tabatabai Yazdi, and Ahmad Naraqi, along with the analysis of relevant legal provisions, clarifies the jurisprudential and legal dimensions of this issue. The findings indicate that collusion, in addition to being religiously and legally prohibited, renders the lawyer's actions void or non-binding and entails severe enforcement guarantees, including civil, criminal, and disciplinary liability, as well as permanent disbarment. Finally, this research offers strategies for protecting the legal profession against conflicts of interest and collusion.