Does being prime minister compel a person to lie? Of course, says Danyl McLauchlan, and thus far in this campaign it’s the more convincing liar with all the momentum.

There’s a moment in Monday night’s NewsHub leaders debate I’ve been thinking about all day. It’s right at the beginning when the debate moderator and NewsHub’s political editor Paddy Gower asks Jacinda Ardern and Bill English “Is it possible to survive in politics without lying?”

Now, all three people up on that stage knows the answer to that question is “No”. One of the most proximate reasons Ardern is up there debating English is because her predecessor Andrew Little made the mistake of telling the truth to the media when asked if he’d thought about resigning in the wake of disastrous poll results. Back when this happened Gower explained to Duncan Garner that this admission meant that Little’s career was over. “He’s broken a rule in politics. You just don’t do that. He should be saying, ‘Yes we’re struggling in the polls, but I could still be prime minister – we could form a government, we could get these guys together.'”

There are countless situations like this in politics where “the rule” is that the politician needs to lie and if they don’t the consequences are catastrophic; countless circumstances where political leaders have to lie for strategic or moral or legal or diplomatic reasons. If, for example, an MP opposes a policy in their portfolio area but the caucus is in favour of it, they’ll need to put on a big grin and march out to a media scrum to argue in favour of a policy they hate, insisting they fully support it. If they don’t then “there’s a split in the caucus” and they’ll get torn to pieces.

Or, once they’re the leader, if one of their MPs is an incompetent who refuses to stand down because they’re unemployable outside of Parliament, the leader can’t admit to that because then they’ll have a rogue MP on their hands, so blundering fools become “hard working and competent members” when their leader is questioned about them. No one believes it, but they have to say it. It’s the rule. It’s a pretty good deal for the gallery: when a politician breaks the rules and tells the truth, they’re finished and the gallery gets a scalp; and if they follow the rules and lie but then get caught they’re also finished, and the gallery gets a scalp.

But not always, because the rules are somewhat mysterious. On Monday finance minister Steven Joyce claimed to have found an $11.7 billion hole in Labour’s fiscal costings, and as far as anyone credible can tell this was a total and blatant lie. But playing by the nebulous rules of political journalism, Gower wasn’t allowed to describe it as a lie in the debate even though, as Ardern pointed out, the entire point of the lie was to manipulate Gower into raising it in the debate casting doubts about Labour’s fiscal credibility in front of over a million viewers.

Instead it was left for the public to make our own judgments, though the public are completely unqualified to make judgments about the accounting rules for line items in the Crowns’ future operating allowance, and informing us about the veracity of complex technical disputes in very high stakes disputes like this would be a useful public service for informed experts – like political editors – to perform. So in certain circumstances blatant lying is a successful and consequence-free political tactic eagerly rewarded by media outlets.

When trying to answer Gower’s original question Bill English was clearly aware that he lied all the time – Gower went on to question him about his role in the Todd Barclay affair – but English seemed reluctant to lie about the fact that his role compelled him to lie. “None of us is perfect Paddy,” he admitted before pivoting wildly and gushing, “What’s also important is trust in a team and we’ve got a great team!”

Jacinda Ardern worked in the prime minister’s office under Helen Clark. She’s been an MP in Parliament for nine years and knows that a core requirement of her job is following the unwritten rules and lying convincingly to everyone’s face all the time. She also knows that one of the rules is that she has to pretend this isn’t the case so in answer to Gower’s question she put on a huge, sincere grin and announced, “I believe that it is possible to exist in politics without lying and by telling the truth,” and assuring Gower that she’d “never told a lie in politics”, before spending the rest of the evening effortlessly gliding away from awkward questions, confidently prefacing all of her subterfuge and evasions with “Let me be absolutely clear.”

The truth is we don’t want our prime ministers to tell us the truth. What we want is for them to convincingly perform the role of prime minister, and part of that role is to lie to us when the unwritten rules demand it and another is to reassure us that they’re always telling the truth and never lie.

Arden seems very qualified to play this role. Bill English was very good at performing the role of finance minister, dour and prudent, gruffly announcing that growth was “a bit grumpy” when we went into a double dip recession, and denouncing his opponents as spendthrifts who would crash the economy by borrowing on international markets at the same time as he was borrowing unprecedented amounts to keep the economy afloat. On Monday night he doubled down on his finance minister’s lie with gusto. He’s in his comfort zone lying about the economy and Crown fiscals.

But he hasn’t figured out how to play the role of prime minister even though this is actually his current job. His performance flickered in and out; for much of the debate it was merely Bill English up there on the stage, hesitant and clumsy, real and thus fake, outperformed and outclassed by Jacinda’s genuine prime ministerial bullshit.

Read more of The Spinoff’s awesome election 2017 coverage here