Is it permissible for the second congregant to stand to the left of the Imam if there is only one congregant to his right and the space is confined?

The Sunnah is for an individual worshiper to stand to the Imam's right. When there is another worshiper, they both stand behind the Imam. This is supported by the actions of the Prophet, peace and blessings be upon him, with Ibn Abbas, Anas, the orphan, Jabir, and Jabbar. It is permissible to stand to the Imam's left if space is limited.