THE only question surrounding the next general election relates to its timing. The outcome is not in doubt. We probably didn't need Thursday's Irish Times opinion poll to tell us but it confirmed what has long been obvious: Fine Gael and Labour will form the next government.

Fianna Fáil is probably not at 17%. Bear in mind it got 25% in the local elections and Labour, put at 24% in Thursday's poll, got less than 15%. But without doubt the two main opposition parties are on course for a thumping majority in the next Dáil.

That should be welcomed. Healthy democracy requires that no one party is in government indefinitely. After dominating for the past 22 years, Fianna Fáil needs a spell in opposition.

There are also plenty of fine politicians in Fine Gael and Labour who deserve a place in the cabinet. The likes of Richard Bruton, Brian Hayes, Simon Coveney, Leo Varadkar, Phil Hogan, Eamon Gilmore, Pat Rabbitte and Ruairí Quinn will make fine ministers. And Enda Kenny, for all the criticism of him, may surprise people as taoiseach. Anybody who has prospered as Fine Gael leader for seven years with barely a hint of dissent should not be underestimated.

So Fine Gael and Labour are the government in waiting. The question now is, when are they going to start acting that way?

Over the past year, the two parties have opposed pretty much every major government decision to address the crisis in the public finances. They have backed every protest group (some with legitimate causes, many with nothing of the sort), objected to every cutback in spending and opposed every tax increase.

A cynic might suggest their opposition to Nama is the result of focus-group research that shows the public is angry about any measure that would involve bailing out the banks and that might be perceived to involve bailing out property developers.

Fine Gael, in particular, is at sixes and sevens over Nama. Two of its respected former leaders have effectively backed the government proposal and privately, many members of its parliamentary party agree with them. There are also mixed signals coming from senior figures as to whether or not they are willing to engage with the government on potential changes to Nama.

The party's finance spokesman, Richard Bruton, is a considered, measured politician who rarely puts a foot wrong, which makes Fine Gael's stance on the banking crisis all the more puzzling. Its good banks-bad banks proposal looks ill-thought-out in terms of the sources of its funding and hugely risky in its impact on the banking system and the future relationship with senior bondholders that both the banks and the country will need to tap for future finance.

Even if it did make sense (and it doesn't), Nama is the only option that the Dáil is going to be voting on. Passionately promoting the Fine Gael proposal, as a worked-up George Lee did on Today with Pat Kenny last week, is starting to resemble a fire engine trundling along at full pelt to the wrong fire.

Labour's nationalisation proposal is more in keeping with the party's ideology but, whether or not one agrees with nationalisation, it doesn't address the crisis in the main banks' balance sheets.

The reality, however much it will be denied, is that if Fine Gael and Labour were in government today, they too would be going with the Nama model. They would also have to implement enormous cutbacks in spending on social welfare, education, health and public-sector pay.

It was fascinating to observe both parties' position papers prior to last April's special budget. Neither of them advocated a rowing back on either the special pension levy on public servants or the withdrawal of the universal medical card for over-70s, yet just weeks earlier they had so bitterly opposed both those measures.

It should be pointed out that Fianna Fáil would adopt exactly the same shameless approach in opposition. And politically, the party's trenchant opposition has played extremely well for it with the electorate.

But with power virtually assured, it is now time for Fine Gael and Labour to reconsider that approach. Garret FitzGerald has already pointed out how important it is to the national interest that the banking and budgetary crises are addressed in the next few months.

However, there are also practical political considerations for the two parties. By opposing every cutback and climbing on the back of lorries at every protest meeting across the country, Fine Gael and Labour run the risk of raising expectations that they have some magical, non-painful solution to the mess that we as a country are in.

There is no magical, non-painful solution to the €20 billion hole in the public finances, and the government-in-waiting needs to start managing expectations in that regard if they want to avoid the electorate turning on them once they get into office and start making tough but unavoidable decisions.

To be fair, it's a tricky one for the two parties. The classic politics of opposition has served them well over the past year. But at some point, they are going to have to start thinking beyond the next general election. There is a slight risk involved, but with Fianna Fáil so unpopular it's pretty minuscule. And the potential prize – two or more terms in government, as opposed to one angst-filled spell before being filleted by a betrayed electorate – is enormous.