A person who is returned as a member of the Parliament shall take the oath of allegiance (whether or not he has taken the oath after being returned on a previous occasion or otherwise than as a member of the Parliament).
He shall do so at a meeting of the Parliament and shall not take part in any other proceedings of the Parliament until he has done so.
If he has not done so within the period of two months beginning with the day on which he was returned, or such longer period as the Parliament may have allowed before the end of that period, he shall cease to be a member of the Parliament (so that his seat is vacant).
Each member of the Scottish Government shall on appointment—
Each junior Scottish Minister shall on appointment take the oath of allegiance.
Subsections (4) and (5) do not require a member of the Parliament to take the oath of allegiance again if he has already done so in compliance with his duty as a member.
In this section, references to taking the oath of allegiance are to taking it in the form provided by the Promissory Oaths Act 1868.