Between General Elections, new Members of Parliament who win their seats at by-elections are introduced individually into the House of Commons.
This normally happens during the week - usually the Tuesday - after their election the previous Thursday.
Introductions take place after oral questions and at the start of public business at 1530.
Accompanied by cheers from the winning side the new MP enters the Commons chamber, bows to the Speaker and walks to the Speaker's table accompanied by two sponsoring MPs, one of whom is often a whip.
The new MP then takes the oath or affirms, signs the test roll and shakes hands with the Speaker before taking their seat on the appropriate side of the House.
The Oath and Affirmation
To take the oath, a member holds a copy of the New Testament, the Old Testament or the Koran and says: "I [name] swear by Almighty God that I will be faithful and bear true allegiance to Her Majesty Queen Elizabeth, her heirs and successors, according to law. So help me God."
If a member objects to this, they may instead "affirm" allegiance: "I [name] do solemnly, sincerely and truly declare and affirm that I will be faithful and bear true allegiance to Her Majesty Queen Elizabeth, her heirs and successors according to law."
However, it is not possible to sit in Parliament without swearing allegiance to the Monarch.
For this reason, Sinn Fein MPs do not take part in parliamentary debates.