With two weeks until polling day, we are at the halfway point of the election campaign.

The first head-to-head debate is over and the major manifestos are now published — we are entering into the business end of the race to form the next government.

But how will a government be formed?

With the numbers in the 33rd Dáil increasing from 158 to 160, the magic number to reach a majority is 80.

Following the pattern in Europe in recent decades, no one party is in a position to form a majority government, so, at best, we are looking at some form of coalition.

The problem is that if opinion polls are to be believed, the road to 80 seats is far from clear.

As I see it, five scenarios are possible and all are fraught.

SCENARIO 1: Fianna Fáil majority government

Some pundits, including Ivan Yates, have Fianna Fáil on course to win around 60 seats and Fine Gael to lose up to 10 seats. My latest estimate has Fianna Fáil winning 55 seats, and Fine Gael in the mid-40s, with neither in a position to form a government.

To get to 80, a lot of work needs to be done.

Both Fianna Fáil and Fine Gael have identified the Green Party as prime candidates and it is clear that Eamon Ryan’s group of three TDs will come back in increased numbers.

On 8% in the most recent Irish Times Ipsos/MRBI poll, the Greens are in the mix to pick up a seat in every Dublin constituency bar North-West and South-Central. On a good day, they are coming back with eight to 10 seats.

And while the bigger parties are taking the Greens’ involvement as a given, internally it is not so straightforward.

Neasa Hourigan, the party’s candidate in Dublin-Central, speaking to me this week, made clear that going into government is not a foregone conclusion. Ms Hourigan said that any decision to enter government must go through a special party conference, and with the scars of the Greens’ previous term in government with Fianna Fáil (2008-2011) still raw, such approval cannot be guaranteed.

She also said that if the party concludes that it would be of greater impact in opposition, then they will stay out.

But take it they go in: that gets you 68 seats, so the obvious next party to look at is Labour.

Brendan Howlin’s hopes of doubling his party’s seat tally, from seven to 14, appear wildly optimistic.

The party will lose Willie Penrose’s seat and there is a concern that Joan Burton’s seat is vulnerable, as are Jan O’Sullivan’s, in Limerick, and Alan Kelly’s, in Tipperary. But they look set to see Áodhan Ó Riordan, Ged Nash, Mark Wall, and possibly Kevin Humphreys, elected, on a good day.

So, if Labour come back with eight to 10 seats, even though Brendan Howlin is very eager to re-enter government, many others in the party are not so sure, not with the party still teetering on the brink. The entry into government is also subject to approval at a special party conference and, like the Greens, it is not certain such a proposal would succeed.

But, again, take it they go in: that gets you to 76 seats, so there would need to be a reliance on even smaller parties, like the Social Democrats and some gene pool independents.

But the kinds of rural independents that Fianna Fáil leader, Micheál Martin, would be looking to would be espousing policies in direct conflict with the Greens, so, again, how could it work?

Overall, this scenario would appear too shaky to succeed.

SCENARIO 2: Fianna Fáil minority government — reverse confidence and supply

If, as I outlined above, either the Greens or Labour refuse to enter government, but Fianna Fáil can get 70 seats or thereabouts, pressure will be on Leo Varadkar and Fine Gael, in the national interest, to facilitate a minority Fianna Fáil-led administration in a reverse confidence-and-supply deal.

While the outgoing government has been stable, it has been woefully unproductive and has long-fingered major decisions on third-level fees, water charges, and property tax reform, to name but a few. It was always meant to be a temporary arrangement and the country can ill-afford a repeat of it.

SCENARIO 3: Fianna Fáil-Sinn Féin coalition

A coalition between Fianna Fáil and Sinn Féin gets you in reach of the 80-seat mark, or over it on a good day.

For the first time, Sinn Féin appear eager to get their hands on power and have changed their stance to being willing to enter a coalition as a minority party.

However — and it is a big ‘however’ — Micheál Martin has dug his heels in, repeatedly ruling out any prospect of a deal with Mary Lou McDonald’s party, and questioning whether the party is run by shadowy, unelected figures.

One wonders, though, just how strong Martin’s resolve would be if the difference was between becoming Taoiseach and not. And Fianna Fáil previously said it would never do coalitions, until it had to with the Progressive Democrats. While such a scenario delivers a majority government, one wonders if the personalities are there to make it work. I doubt it.

SCENARIO 4: The grand coalition

In what was the stand-out moment of the first TV debate, on Virgin Media, Taoiseach Leo Varadkar put the offer of a full coalition with Fianna Fáil on the table.

“We have to be grown-ups. My preference would be to form a coalition with old partners, like Labour and independents; maybe new partners, like Greens.

“But if it’s the case that people vote in a certain way, and the only way we can form a stable government is for Fianna Fáil and Fine Gael to work together, well, I’m willing to do that,” he said.

It is compelling. The parties are identical on policy and such a deal would allow for a fundamental realignment of Irish politics, between right and left. It would deliver the numbers for a strong majority government seeking to stay in power for five years.

While not rebuffed immediately by Martin, Varadkar got his answer the next day, when the Fianna Fáil leader shut the door on the idea, saying the country wants and needs a change of government. But let’s see how resolute he is on the far side of an election.

It would be a rocky arrangement, as many in both parties hold deep personal animus regarding their rivals.

SCENARIO 5: Another election

If, after a prolonged period, no workable arrangement can be arrived at and a government, majority or minority, can’t be formed, the nuclear option is for another general election to be called.

Nobody, nobody would want that. While the public will have its say on Saturday, February 8, we have a long wait for a government to be formed.