Gerry Adams has officially resigned from his Westminster seat and become Crown Steward and Bailiff of the Manor of Northstead, the Prime Minister said today.
The Sinn Fein leader, who is standing in the upcoming Irish election, resigned his West Belfast seat in a letter to Commons Speaker John Bercow.
But there was confusion over whether he had formally applied to the Chancellor for an office of profit under the Crown, a title that makes a person ineligible to sit in the Commons.
At Commons question time, David Cameron told MPs that Mr Adams had agreed to become "baron of the Manor of Northstead".
His confirmation came after DUP spokesman Nigel Dodds said: "You may be aware that one of the Members elected to this House has decided to emigrate - and you may want to chalk that up as one of your achievements.
"The said Member for West Belfast, Gerry Adams, seems to be embarrassed about applying for an office under the Crown, an office for profit - although he has shown no such embarrassment of profiting from his office in this House for many years at taxpayers' expense.
"When will you deliver on your pre-election pledge to hard-pressed taxpayers that you will abolish parliamentary money for parliamentary purposes going to those who do not fulfil their parliamentary duties?"
Mr Cameron replied: "First of all, just in case people haven't caught up with the news, you are quite right that the Honourable Member for West Belfast has accepted an office for profit under the Crown, which of course is the only way you can retire from this house."
To laughter, he added: "I'm not sure that Gerry Adams will be delighted to be a baron of the Manor of Northstead. But nonetheless I'm pleased that tradition has been maintained.
"In my view, what we should be aiming for is for all Members who are elected to take their seats in this House. That is what should happen.
"And if some Members have a problem with what that entails, they ought to look at a remedy for that and they should come and talk about that. I think that is the most important thing we can achieve."