Whether or not Labour changes its leader, the MPs gathered in Wellington today need to stop blaming everyone else and take a long, hard look at themselves

Labour MPs travelling to Wellington today for their first post-election caucus will have their heads crammed full of theories, accusations and advice from all and sundry. But here's the message for them to keep front and centre whichever direction they choose as a party: You've got to earn it.

As the party has wrestled with itself in the past three years, the attitude of some MPs has seemed to be that politics works in cycles and, whatever they do, Labour's "turn" will come again soon, in the same way the sun rises and sets.

What's true is that governments tend to lose elections, rather than oppositions winning them. But to interpret that to mean Labour can faff around until Key & Co sink themselves or the public gets bored with them is foolish in the extreme.

Not only does it ignore the modern realities of MMP, the rise of the Greens (and New Zealand First), the shrinking of its own base, and the popularity of John Key, it misses the glaring point that despite a barrage of questions about National's integrity and decency in government, voters preferred to trust it with power. Even more power than before. Labour just didn't look like a government-in-waiting; it didn't look ready.

And to merely blame that lack of trust on the shadow Kim Dotcom and Hone Harawira cast over the left is to miss the point again.

You've got to earn voters' trust. You've got to look disciplined, competent and as if you have the interests of the nation at heart. That's what swing voters want to see, as much as "centrist" policies.

I don't think you can say that the policy mix is perfect, as policies send messages of their own and need to be part of a single strateegy. But it wasn't policy that lost the election.

I don't think you can say the organisation as perfect, as turnout was still lower than the left would like and it seems money has always been a problem for Labour since Mike Williams's presidency ended. But it wasn't organisation that lost the election.

Some are blaming the media. Were they the problem? Sure some deserve criticism, but that's nothing new for either side. What those blaming the media fail to understand is the power of the narrative and how voters see the big picture of politics. For example, you might reaosnably argue that Bill English's 'no new ideas' moment on The Nation was as telling as Cunliffe's CGT pause at The Press debate. But from the public's view, one fitted the narrative of a man who had form when it came to not knowing the detail of his own policy, while the other was a lapse amidst six years of perceived wider competence.

So those gathering MPs shouldn't waste time blaming others, they should simply look hard at themselves.

Put simply, it was Labour's people that lost the election. The leader, the past leaders, the MPs. All of them. Voters looked at them and – let me stress this again – even with all the doubt created by Dirty Politics (not to mention asset sales and more), still trusted them less than National.

Let's not pretend this election was lost in the campaign – it was lost through Shearer's communication problems, Cunliffe's lack of a plan when he took the leadership and inexplicable disappearance last summer, and the factions refusing to support the guy in charge.

Because of the choices made inside that Labour caucus, the party wasted three years.

That first term after 2008 was the time to fight over the soul of the Labour Party, to inject some new ideas and new talent. Phil Goff was the perfect caretaker and allowed some challenging ideas through, such as raising the super age and a capital gains tax. But the fighting continued even after Goff. Shearer failed to perform, Cunliffe failed to accept defeat, factions failed to put the wider party first; there's plenty of blame to go around.

Those in the centre of the party saw Shearer as their salvation, but the reality didn't match the idea.

Those on the left of the party agitated for Cunliffe hoping he could win on a more blatantly left-wing platform. But if that as ever going to be possible, it would only have been in 2011 when a "bugger the markets" approach may have had some traction. That moment has passed.

So Labour now needs to make a choice: either become a niche left-wing party of no more than 25 percent support or reach back into the muddy centre, take the fight to National (and New Zealand First) and aim again for the mid to late 30s. And that choice needs to be made swiftly so that the narrative can be changed and voters has enough time to learn to trust Labour again.

The problem is that Labour has no more room for mistakes. As Goff has wisely said, it needs to "measure twice and cut once". Whoever is leader at the start of 2015 needs to be the leader in 2017, or it'll be hopeless.

I don't know who that leader should be. Can Cunliffe change people's first impression of him and therefore change the narrative? Or is a fresh face needed? If so, the same problem remains as before – there's no obvious leader who ticks all the boxes

But what those MPs need to remember as they choose which path to take is that they have to earn a chance at victory in 2014; if they merely wait for their turn, it may never come.