Boris Johnson has formally resigned as an MP under the archaic process of being appointed to be Steward and Bailiff of the Three Hundreds of Chiltern.

The move follows the former prime minister’s dramatic resignation announcement last week, in protest at his trimmed-down honours list and expected ruling by a parliamentary committee that he lied to MPs over partygate.

But he technically remained an MP until his exit from Parliament was formally triggered on Monday, when Chancellor Jeremy Hunt appointed him to the historical position – which in modern times has been used to facilitate the resignations of MPs.

“The Chancellor of the Exchequer has this day appointed Alexander Boris de Pfeffel Johnson to be Steward and Bailiff of the Three Hundreds of Chiltern,” the Treasury said.

Elected MPs are in theory unable to resign and must become disqualified if they wish to quit Westminster while Parliament is sitting.

Holding the Chiltern Hundreds or the Manor of Northstead titles immediately disqualifies a person by law from being an MP and therefore removes them from the House of Commons.

Former culture secretary Nadine Dorries and ex-minister Nigel Adams also said they were standing down as MPs after Downing Street published Mr Johnson’s resignation honours list on Friday without their names.

Mr Johnson’s camp accused Rishi Sunak of having “secretly blocked” their peerages, amid a public slanging match between the current and former prime ministers.

Mr Adams pipped Mr Johnson to the post with his formal resignation on Monday, with Mr Hunt naming him the Steward and Bailiff of the Manor of Northstead minutes before the ex-prime minister’s appointment.

The arcane title held by Mr Adams alternates with the Hundreds.

He will likely only stay in the position briefly until Ms Dorries takes it on to formally quit.

Parliament’s website says: “The Steward and Bailiffs of the Chiltern Hundreds and of the Manor of Northstead were positions traditionally paid for by the Crown.

“In modern times they are unpaid, formal titles that are applied for when an MP needs to disqualify themselves from the Commons.

“An elected MP has no right to resign: unless they die or are expelled they must become disqualified if they wish to retire before the end of a Parliament.

“By law, taking on one of these titles immediately bars a person from being an MP.”