CLIVE Lewis has become the only Labour MP of this session so far to be sworn into Westminster "under protest".
The representative for Norwich South is a keen republican and made his position clear as he took the affirmation.
He joined two SDLP MPs who expressed their pro-republic sentiment during Tuesday's swearing-in ceremony.
MPs are required by law to make an oath or affirmation of allegiance to the Crown and are not allowed to speak in debates, vote or receive their salary until they do so.
Labour MP Lewis said before his affirmation: “I take this oath under protest and in the hope that one day my fellow citizens will democratically decide to live in a republic.”
Earlier, SDLP MPs Colum Eastwood and Claire Hanna made clear that they were affirming allegiance to the King in order to do their job as MPs.
Party leader Eastwood said: “I read out this empty formula in order to represent my constituents but it’s under protest.”
He went on: “I do solemnly, sincerely and truly declare and affirm that I will be faithful and bear true allegiance to His Majesty King Charles, his heirs and successors according to law.
“My true allegiance is to the people of Derry and to the people of Ireland.”
Hanna also took the opportunity to speak in Irish as well as English.
“In friendship and in hope of a reconciled new Ireland, my allegiance is to the people of Belfast South and Mid Down," she told the Commons in her native language.
She then said in English: "I say these words in order to serve them.”
