Who is responsible for establishing congregational prayer?

The one with the most right to authorize the call to prayer (Iqamah) is the Imam; prayer should not be established except with his permission. This is based on the statement of Ali (may Allah be pleased with him): "The Mu'adhin has more right over the Adhan, and the Imam has more right over the Iqamah." As for who directly performs it, it is preferable that the Mu'adhin who called the Adhan for the prayer performs it, based on the Prophet's (peace and blessings be upon him) statement: "Indeed, the brother of Sada' called the Adhan, and whoever calls the Adhan, he should perform the Iqamah."