Campaign trail: Joe O’Brien from the Green Party meets Imelda Natin with her dogs Sophie and Suzie in Malahide village. Photo: Steve Humphreys

The posters are now on the lampposts, finally catching up with the tempo of canvassing over the past months.

On the junction of Main Street and Church Road in Malahide, there was a mixture of bemusement and puzzlement as Joe O'Brien did a leaflet drop.

O'Brien is the Green Party candidate in the forthcoming Dublin Fingal by-election.

Passers-by weren't quite sure what they were being asked to vote on until reminded Independent Clare Daly's departure to Europe has created a local vacancy.

The stresses and strains of the Dublin commuter belt are shown in the issues coming up on the street, like housing and public transport in a rapidly developing part of the capital.

But repeatedly, the new second runway at Dublin Airport comes up. If it proceeds, the flightpath will be over houses in Malahide and neighbouring north Portmarnock. O'Brien and his party have the advantage of long opposition to the runway being built.

The Greens have plenty of pedigree in the constituency, which encompasses most of north county Dublin.

Former party leader Trevor Sargent was a flagbearer in this constituency during his nigh on 20 years as a TD. Daly took the non-main party seat here in 2011 during the Greens' meltdown. Now they want it back and there's a fair wind behind them.

"I think people are looking at it in a very practical way. They understand the other parties are represented here. The Green message has been very prominent worldwide and locally as well over the last 12 months," O'Brien says.

"There is housing going up, but it's the same old problem, the same overarching problem in that the infrastructure isn't going in.

"We have trains that are overcrowded. We have families that can't get places for their kids in school.

"That's really the big overarching issue that I'm seeing on the doors."

The official starting gun was fired last week with the moving of the writs for the four by-elections in Dublin Fingal, Dublin Mid-West, Wexford and Cork North-Central.

The votes were sparked by the elections of Daly, Frances Fitzgerald, Mick Wallace and Billy Kelleher to the European Parliament.

Until 10 days ago there was uncertainty if the four by-elections would proceed as a full general election was still on the table.

Taoiseach Leo Varadkar has been playing down Fine Gael's prospects, saying it will be difficult for his party to win any of the four seats.

None more so than in Dublin Fingal where the party is writing off the chances of former deputy leader and ex-health minister Dr James Reilly. Anything better than humiliation is regarded as a bonus.

Fianna Fáil Senator Lorraine Clifford-Lee is the early and clear favourite to take the seat.

"Her's to lose" is the phrase commonly used by opponents about Clifford-Lee's prospects. It's a dangerous position to be in as by-elections are so notoriously unpredictable.

Due to the national spotlight, what can seem like minor controversies can garner a lot of attention.

Also in the race are Sinn Féin councillor Ann Graves, Labour Party councillor Duncan Smith, the Social Democrats' Tracey Carey and Independent Gemma O'Doherty. Daly has yet to anoint any potential successor. There has been plenty of speculation but no definite name emerging.

Of the four by-elections taking place on November 29, O'Brien represents the Greens' best chance of being in contention for a win.

O'Brien's performance will be watched closely across the political spectrum.

Last week, a strategist with one of the main parties told the Irish Independent the number of Green TDs after the general election could even be in the mid-teens if their current growth trajectory continues.

The concentration of their vote in key constituencies and transfer friendliness means a vote surge would deliver a disproportionate seat gain.

Not even the Greens themselves appear to realise their potential.

Dublin Fingal would be high on the list of gains in a general election with a Green wave attached.

Before that, the collection of by-elections will serve as a stock-take for all the parties.

After the European and local elections breakthrough in the summer, they serve as an acid test for the Greens.

O'Brien is conscious the spotlight is on him. As with all rising political parties, the hard part is putting policies into practice.

On the question of the Greens going into government after the general election, he supports party leader Eamon Ryan in keeping their options open.

"If you're running for election, I'm assuming you want to be in government and you want to make change.

"And you have to be willing to get your hands dirty with people you don't necessarily agree with and there's a hell of a lot I don't agree with in terms of Fianna Fáil and Fine Gael," the Skerries councillor says.

Originally from Cork, the 42-year-old has lived in the area for 15 years and now has a young family.

O'Brien works as a project manager with the Immigrant Council. He also represents the northern end of the constituency, where towns like Balbriggan and Donabate have seen a large rise in the non-national population. Reflecting the current national debate, O'Brien expects immigration to arise in the campaign.

He views the changing demographics as a "hugely positive thing that has happened to Ireland".

Irish Independent