New MPs go through an odd little ceremony when they take their seat in the Commons.
I watched it last week. Summoned by the Speaker, they bow, walk forward five paces, bow again, then they take an oath to be 'faithful and bear true allegiance to Her Majesty Queen Elizabeth, her heirs and successors'.
They sign the register, shake hands with the Speaker and they are now an MP, able to speak, vote and ask questions in the Commons. The whole process takes about 90 seconds.
The man taking the oath last week wasn't Francie Molloy, the newly-elected MP for Mid Ulster, but Mike Thornton, the Lib Dem victor in the Eastleigh by-election.
The five Sinn Fein MPs refuse to sit in the Commons, but they have offices and staff at Westminster and can claim expenses in the same way as other members.
The decision to grant them access to the perks and privileges of the House, without taking the oath, continues to stoke controversy, 12 years after the decision was taken by Tony Blair's government.
Sinn Fein MPs are seen around Westminster more regularly since they ended double-jobbing, but the place where their presence is not felt, and is most needed, is in the chamber.
At Northern Ireland Questions last week, for example, Secretary of State Theresa Villiers was asked about dissident violence, the impact of benefit changes, youth unemployment, parades and funding of political parties.
Yet 28% of our elected representatives are never present to put their points to Mrs Villiers.
The DUP's William McCrea raised the issue with ministers last week, calling on the Government to "grasp the nettle and stop this intolerable abuse and inequality of funding".
Minister of State Mike Penning said "this is a matter for the House".
There appears to be no appetite either to change the oath of allegiance, or to stop Sinn Fein's parliamentary privileges.
As for Francie Molloy, he will be making his first trip to London as an MP tomorrow to take part in the St Patrick's Day celebrations. Michelle Gildernew and Conor Murphy will also be in town.
"We wanted to up our contact with politicians in London. Now we would have one, or more, of our MPs in London every week," a Sinn Fein spokesman told me.
"We have meetings with ministers and shadow ministers and with members of the Northern Ireland select committee. We are as active as any other MPs."
So will this heightened level on engagement lead to a shift in policy on sitting at Westminster?
"Absolutely not," is the response.