What is the ruling on pulling a prayer rug from under the Imam to pray on it due to lack of space, when there is another rug under him?

If taking the prayer rug causes disturbance to the Imam while he is praying, then it is prohibited, because disturbing a worshipper is forbidden by Islamic law. Anything that disturbs a worshipper's prayer and distracts him from it is akin to passing in front of a worshipper. However, taking the prayer rug before the Imam begins the prayer, or if it does not entail any disturbance to him, then there is no objection to it. If the prayer rug belongs to someone, the owner's permission is required to use it.