Michael O'Regan, Parliamentary Reporter, analyses the current state of play in the European election constituencies
Dublin (4 seats)
Outgoing: Mr Niall Andrews, FF; Ms Mary Banotti, FG; Mr Proinsias De Rossa, Labour; Ms Patricia McKenna, Green Party.
As in the other constituencies, a change of personnel, at least, is inevitable, given the retirement of Mr Andrews and Ms Banotti.
Fianna Fáil is pinning its hopes on Dublin South East TD and former junior minister, Mr Eoin Ryan, and the colourful and controversial Lord Mayor, Mr Royston Brady.
Mr Ryan was bitterly disappointed when he was dropped from the junior ministerial ranks after the last general election. Winning a place in the European Parliament would be a consolation prize.
He comes from an impeccable Fianna Fáil tradition. His father, Mr Eoin Ryan, was a member of the Seanad, while his grandfather, Dr Jim Ryan, was a prominent government minister under Éamon de Valera and Seán Lemass.
This political "blue blood", as well as his base south of the Liffey, makes him favourite to replace Mr Andrews. However, Mr Brady, with his high profile as Dublin's first citizen, is a strong candidate with an appeal to young voters.
Labour's Mr Proinsias De Rossa is a strong favourite to retain his seat. He has worked hard during his term in Europe, maintaining contact with the Labour grassroots. Labour is hoping that his running mate, Ms Ivana Bacik, Reid professor of criminal law, criminology and penology in Trinity College, could pull off a surprise and help take two seats for the party. This was last achieved by Labour in 1979, when its then candidates, Dr John O'Connell and Mr Michael O'Leary, both won seats, despite bitter rivalry.
There is likely to be candidate rivalry this time, too.
Ms Patricia McKenna has been a strong electoral performer, but she could come under pressure this time from Sinn Féin's Ms Mary Lou McDonald, who has the best chance of taking her party's first European Parliament seat in the Republic.
The party has used every opportunity to promote Ms McDonald, and she has never been far from Mr Gerry Adams's side at various photo opportunities.
Much could depend on the transfers of Socialist Party TD for Dublin West, Mr Joe Higgins. Last time, Ms McKenna received 3,844 transfers from Mr Higgins, compared to 1,412 for the then Sinn Féin candidate, Mr Seán Crowe. Although Mr Crowe went on to win a Dáil seat in Dublin South West, he did not have Ms McDonald's media profile at that time.
Ms Mary Banotti's retirement is a further blow to Fine Gael, following its rapid decline in the capital in the last general election. Last time, Fine Gael had an impressive 30.09 per cent of the vote, but now the struggle is to first find a high-profile candidate.
Party official Ms Katherine Meenan and barrister Mr Colm Mac Eochaidh have declared an interest in running. However, it may fall to the Dublin South Central TD, Mr Gay Mitchell, to be the standard bearer. He is considering his position. Mr Mitchell would be a formidable candidate.
The PDs suffered a setback with the withdrawal of Dublin South TD, Ms Liz O'Donnell, from the race. The party may now go outside its ranks to find a candidate.
East (3 seats)
Outgoing: Mr Liam Hyland and Mr Jim Fitzsimons, FF; Ms Avril Doyle, FG; Ms Nuala Ahern, Green Party.
Fine Gael's fortunes look considerably brighter in this constituency, which has been reduced to a three-seater.
Ms Doyle has been joined on the ticket by the high-profile agricultural journalist, Ms Máiréad McGuinness, but the prospect of two seats for the party is an outside chance. However, her presence in the contest guarantees the retention of Fine Gael's one seat.
Labour is hoping to make a breakthrough with Mr Peter Cassells, chairman of Forfás and executive chairman of the National Centre for Partnership and Performance. He became a national figure as general secretary of the Irish Congress of Trade Unions (ICTU).
Although his profile has declined in recent years, his trade union background is likely to strike a chord with Labour voters.
Mr Hyland and Mr Fitzsimons are retiring, and Fianna Fáil is fielding the Minister of State and Carlow-Kilkenny TD, Mr Liam Aylward, and Louth's Mr Séamus Kirk, chairman of the parliamentary party.
Mr Aylward, a legendary vote-getter in his constituency, is a strong favourite for a seat, but Mr Kirk will have a fight on his hands to retain the second seat.
The Green Party, too, could be under pressure with Ms Ahern's retirement. Her replacement, Ms Mary White, polled close on 5,000 first preferences in the Carlow-Kilkenny constituency in the general election, and will put up a strong challenge. But a galvanised Labour organisation could see her under pressure from Mr Cassells.
The Sinn Féin candidate is Mr John Dwyer, a trade union official from New Ross who has his eyes set on a Dáil seat in Wexford.
South (3 seats)
Outgoing: Mr Gerard Collins and Mr Brian Crowley, FF; Mr John Cushnahan, FG; Mr Pat Cox, Independent.
This constituency, formerly Munster, has also been reduced to a three-seater, putting the second Fianna Fáil seat in serious jeopardy. Mr Crowley polled an incredible 154,195 first preferences in the last election and can hold his seat even with an anticipated decline in support.
Mr Cox, as President of the European Parliament, also seems set to retain his seat, given his high profile.
That would leave Mr Collins, Fine Gael's Mr Simon Coveney, replacing Mr Cushnahan who is retiring, and Labour's Mr Brendan Ryan in contention for the third seat.
Mr Collins is a formidable politician, who served as a senior minister before opting for Europe. But he could be facing his toughest electoral battle, with Mr Coveney a strong prospect to take the third seat.
Fianna Fáil activists in the South have privately expressed the view that the Government might appoint Mr Cox to an international post to ensure the safety of its second seat. But, so far, there has been no word from Government sources that this will happen.
Mr Crowley, who has a broad appeal, is resisting a vote management exercise in the constituency. Mr Collins will, no doubt, argue that it would not be good for the constituency to have a Cork-dominated representation in Europe. But will the voters buy that?
Sinn Féin is running Mr David Cullinane, from Waterford, a member of the party's ardchomhairle.
The Green Party candidate is Mr Chris O'Leary.
North West (3 seats)
Outgoing: Mr Seán Ó Neachtáin, FF; Mr Joe McCartin, FG; Ms Dana Rosemary Scallon, Independent.
Mr Ó Neachtáin's performance will be interesting to watch. He replaced Mr Pat "The Cope" Gallagher in 2002, and efforts to replace him on the ticket with junior Minister, Mr Frank Fahey, failed at a recent convention. It was a victory for the grassroots over party headquarters.
His running mate, Donegal-based Minister of State Dr Jim McDaid, has the higher profile. But will the surge among the grassroots for Mr Ó Neachtáin continue and send him back to Europe?
Fine Gael is running the Mayo-based senator, Mr Jim Higgins, and the former TD and senator from Clare, Ms Madeleine Taylor Quinn. Mr Higgins is considered the frontrunner to replace Mr McCartin.
There will be considerable interest in the performance of the two Independents, Ms Dana Rosemary Scallon, outgoing MEP, and the TD for Sligo-Leitrim, Ms Marian Harkin.
Ms Scallon is thought to be vulnerable to a strong challenge.
Last time, Ms Harkin polled 47,372 first preferences compared to Ms Scallon's 51,086.
Labour is fielding Mr Hughie Baxter, a party activist in the Longford-Roscommon constituency, while the Sinn Féin candidate is Mr Pearse Doherty, a party activist in Donegal South-West.