A Garda whistleblower, a former world champion athlete, a security analyst, two former TDs, a host of current Senators and a prominent political tweeter are among those who could become Irish MEPs in the next five years without ever facing an election.

Unlike domestic political institutions, byelections are never held when a seat in the European Parliament is vacated by an MEP, either by resigning or by death.

Instead, candidates and parties are required to provide a list of replacements who can substitute for them if the seat becomes vacant.

Of the outgoing 12 MEPs, three were substitutes who were on the replacement panel of the politician they replaced.

Two of the elected MEPs – Alan Kelly of Labour and Joe Higgins of the Socialist Party – resigned their seats when elected to the Dáil.

They were replaced by Phil Prendergast and Paul Murphy respectively.

The third replacement Emer Costello assumed the seat vacated by her Labour colleague Proinsias De Rossa on his retirement. All three are standing for re-election.

So while most candidates with the exception of one or two (including Luke Ming Flanagan) have declared they will serve the full five-year term, there is a strong likelihood on the evidence of past parliaments that at least one or two substitutes will become MEPs.

Activist
The choice of substitutes is interesting, especially among Independent candidates. Mr Flanagan has chosen the Garda whistleblower John Wilson as well as his personal assistant Pat Fitzpatrick, a former Green Party activist.

Dublin Independent candidate Nessa Childers has chosen former Army officer and security analyst for The Irish Times Tom Clonan, as well as businesswoman Glenna Lynch, a regular political tweeter.

Fateful
She is also the person who challenged presidential candidate Sean Gallagher's business acumen on the fateful Frontline programme that changed the course of that election in October 2011.

The Fine Gael Senator and former world champion athlete Eamonn Coghlan is Brian Hayes’s first substitute in Dublin.

Two former TDs are also marked down as replacements, both in Midlands North West.

They are Niall Blaney who is on the Fianna Fáil list and former Independent TD for Co Monaghan Paudge Connolly, who is Marian Harkin's first substitute.

There are seven Senators among the replacements: Trevor Ó Clochartaigh (Sinn Féin); Catherine Noone (Fine Gael); Eamon Coghlan (Fine Gael); Michael Darcy (Fine Gael); Colm Burke (Fine Gael); Ned O'Sullivan (Fianna Fáil); and Mark Daly (Fianna Fáil).

Former lord mayor of Dublin Andrew Montague is Emer Costello’s sub in Dublin

Ex-mayor of Kilkenny Malcolm Noonan is Green Party candidate Grace O'Sullivan's replacement in the South constituency.