A grey stone Irish Celtic cross, partly hidden by a taxi rank and facing on to a drab square of shop units, is one of the few reminders of Finglas village’s connection to the Easter 1916 rising against British rule and Ireland’s subsequent war of independence.

In the heart of the Dublin North-West constituency, the cross memorialises Dick McKee, a local republican hero whose battalion was the last to surrender in Easter week 1916. McKee was killed four years later while attempting to escape from British custody at Dublin Castle – then the seat of the empire’s control over Ireland.

Today the political battles around Dublin are conducted peacefully, as the parties and movements that almost all draw their lineage from the events at Easter 100 years ago compete for votes in the final week of the Republic’s general election campaign. And Dublin North-West will be one of the most carefully watched districts next weekend, as the ballot boxes from Friday’s election are opened, in determining the make-up of the next Irish government.

This three-seater constituency is a totemic one, and the destination of the final seat here will have an impact on the shape of the new Dáil (Irish parliament). Two candidates are red-hot favourites to be returned: the hugely popular former IRA activist and Sinn Féin TD Dessie Ellis and the Social Democrats’ TD, Róisín Shortall.

The struggle for the last seat will then be between the two parties forged in the fire and blood of the Irish civil war when one side of the republican movement accepted, and the other bitterly opposed, the 1921 treaty that ended the Anglo-Irish war and partitioned the island into two territories – Northern Ireland and the Republic.

If the ruling Fine Gael party candidate, Noel Rock, fails to take the third seat, it may signal that the party of the taoiseach, Enda Kenny, could emerge as the largest force in the Dáil but without anywhere near a working majority.

For Fianna Fáil, the party founded by Eamon de Valera, who unveiled the McKee memorial back in 1950 when his leadership of Ireland was unassailable, taking the third seat will demonstrate that the party is back from the dead. The party crashed from 71 seats to 20 in the 2011 general election and its candidate, Paul McAuliffe, will be hoping to change things around.

On the electoral campaign trail in one of the middle-class ends of this constituency, which runs up to the perimeter of Dublin airport and is bisected by the M1 motorway connecting the Irish capital all the way north to Belfast, Shortall refuses to discuss the possibility that she might be among a slew of leaders of smaller party groupings and independents who will be the “kingmakers” of a new coalition. Wearing a scarf the same colour as the purple of Ireland’s newest party, the Social Democrats, the former Irish Labour TD, who quit that party over its participation in the last government, Shortall was constantly summoned to the doors of semi-detached private houses on a bone-chilling, cloudless Thursday night on the stump.

One pensioner, Jack Kelly, called her into the house to protest against one of the most hated companies in modern Ireland: Irish Water, the body set up to run the new equally despised water charges. Tens of thousands have taken part in demonstrations across the Republic during the lifetime of the outgoing Fine Gael-Labour government against the introduction of water charges – a condition imposed by the International Monetary Fund and the European Central Bank when they bailed Ireland out of national bankruptcy six years ago.

“We’ve been here 50 years and we have never had leaks like that outside our house,” Kelly said, pointing to a massive puddle of muddy, squelchy, drenched soil just outside his garden. “Those leaks only started when they started putting in their water meters. You ring them up and they keep you holding for ages, they don’t respond properly to your complaints,” the OAP said. Shortall assured him that she would take up his case, while in turn being assured that there were two first-preference votes for her in the Kelly household.

A few doors away the Social Democrat TD met an off-duty female member of the Garda Síochána, the police, wearing a Minions T-shirt. The officer, who asked not to be named because she had not been authorised to speak to the media, said she was disillusioned with the current government as they had cut public servants’ pay, including frontline Gardaí such as her and her boyfriend.

Referring to the current crime war in Dublin that has claimed two lives, she said: “They talk about deploying extra officers to fight the crime gangs but I’ve been fighting crime on the streets ever since this government took over. And in that time our numbers and our wages were cut. I recently worked out that a friend of ours, who is a secretary working in the private sector, is €115 better off than me and my partner per month.”

Asked if she would consider offering a second or third preference to Sinn Féin – the other main political force in Dublin North-West – she said she objected to the party’s proposal to abolish the Republic’s non-jury Special Criminal Court.

“You can’t get rid of a court that helps put terrorists and gangsters in jail. If you just tried these type of people by jury, their friends would intimidate jurors. It’s a crazy idea,” she added.

Outside the two officers’ home, Shortall said the Fine Gael message to voters that they have secured an economic recovery combined with promises of tax cuts was not resonating with vast sections of Irish society. “On the doorsteps of both working-class areas like Finglas, and middle-class areas like Whitehall, we are not hearing about any demand for tax cuts. It’s all about restoring good public services, making child care available, improving the health service. People prefer those things to tax cuts,” she said.

The magic number in this election is 79 – the number of seats any government requires in the 158-strong Dáil to get a working majority. An internal survey by one of Ireland’s election number crunchers seen by the Observer suggests that Fine Gael might only secure 55 seats while their current coalition partners, Labour, will be lucky to scrape back with 10–14 seats short of that elusive figure. The Observer also understands that under no circumstances will Fianna Fáil consider a “grand coalition” with Fine Gael to govern.

Which brings the minority parties such as the Social Democrats and the independents into play as kingmakers after 26 February.

“I am not getting into a numbers game at this stage,” Shortall said as her team of volunteers in their early 20s and 30s pressed for her to move through streets packed with the vans of the self-employed and the cars of the public servants who have taken such a hit during the recession. “We are not into making idle promises, as this was the failing of other parties in the past. Let’s just see what happens next week.”

According to the Historical Tour of Finglas, the spot where the McKee memorial cross now stands was where criminals were placed in the stocks and publicly humiliated until 1702. Although the stocks were removed to the grounds of a local church in the same century, if the coalition parties, Labour and Fine Gael, both fail to return their candidates to the Dáil in Dublin North-West it will result in the humiliating spectacle of Kenny having to search for fresh allies to form a new government; in order to make him the first ever Fine Gael leader to be reelected as prime minister since the war of independence, when Dick McKee lost his life.

BALLOT-BOX COMPETITORS

FINE GAEL The centre-right party descended from that wing of the IRA that accepted the 1921 treaty. Pro-free market, pro-European and increasingly socially liberal, currently led by Enda Kenny but whose future potential leader, Leo Varadkar – gay, half-Irish/half-Indian – personifies multi-ethnic, pluralist Ireland.

FIANNA FÁIL Formed by the state’s founding father, Éamon de Valera, this centrist party was a classic catch-all populist movement which could appeal equally to urban working-class trade unionists, farmers and later property speculators and builders. It was the party’s relationship to the latter social group that mired it in planning corruption and allegations of sleaze. Under its leader, former minister Micheál Martin (pictured left), it is likely to make a recovery in this election.

SINN FÉIN Once umbilically linked to the Provisional IRA, the party led by Gerry Adams has adopted a leftist oppositional stance on austerity cuts and the IMF-ECB bailout of the Irish economy, accusing both the bigger parties of selling out Ireland’s sovereignty.

LABOUR The oldest party in the state and founded before the 1921 treaty and the resulting partition. Rooted in the Irish trade union movement, its decision to enter a coalition with Fine Gael after the 2011 general election has exposed it to charges of treachery from its leftist opponents. Given its support for the coalition’s austerity measures, Labour under it leader Joan Burton, the deputy prime minister (pictured right), faces a Liberal Democrat-style wipeout at the polls.