A Member of Parliament (MP) has powers given by the monarchy. Therefore, an MP represents all the people living in his or her constituency, but must swear an oath of allegiance, not to his or her constituents, but to the King or Queen and all their heirs and successors. If they do not do this, they cannot take their seat, receive a salary, or take part in any voting, as in the case of the nationalist Sinn Féin MPs from Northern Ireland.
The oath, or affirmation, also refers to ‘God’, but an agreed alternative wording is acceptable and a variety of holy books is available for different religious persuasions. The basic version is as follows:-
“I swear by Almighty God that I will be faithful and bear true allegiance to His/Her Majesty King/Queen [Name}, his/her heirs and successors, according to law. So help me God.“
This process must be performed at the start of every new Parliament after a General Election and every change of monarch, as occurred in 2022:-
(Image: UK Parliament at Flickr.com / CC BY-NC-ND 2.0)