Who do you trust?

At the time, John Howard’s opening parry of the 2004 election seemed breathtakingly audacious given he was the man who would “never ever” introduce a GST and had unleashed the concept of “core” and “non-core” promises on an unsuspecting electorate. But those four little words went straight to the electorate’s doubts surrounding the lack of experience of Labor’s neophyte leader Mark Latham and his competence to run the economy.

Fast forward to the present day. All the polls suggest that Prime Minister Tony Abbott may suffer a trust deficit. But that is not stopping him re-purposing Howard’s parry to fit Opposition Leader Bill Shorten.

Shorten’s problem is that, if anything, he is more vulnerable even than Latham.

Not only that, Abbott is flexing every muscle to reduce Shorten’s targets of opportunity. In large measure he is succeeding, aided by the opposition’s fears in some cases and abetted by its mishandling of others.

That politicians lie comes as no surprise to journalists, nor to many voters who see dishonesty as the fundamental operating principle of their elected representatives:

How do you know a politician is lying? Their lips are moving.

So the old cliché goes.

However, the exposing of Shorten as having publicly lied over talking to Kevin Rudd about pulling his numbers away from Julia Gillard in 2013 is much more damaging than that. In close to two years as Labor leader, Shorten has neither built the profile nor provided the performance that renders him prime minister-in-waiting rather than fragile whinger-in-chief.

If the opinion polls are correct, Shorten’s support – and that of the Labor Party – is almost entirely a function of public perceptions of Abbott’s performance. Abbott falls, Shorten rises – and vice versa. That alone exposes Shorten to attacks on his character, even from a prime minister who has problems of his own in this area.

Gillard never recovered from her carbon tax “lie”. Her admission polluted perceptions of Labor until its defeat in 2013 – and beyond. And here lies one of the dangers for Shorten. It is not just that he is a self-confessed liar, but his admission is a reminder to voters that Labor had fibbed its way into office in 2010.

Worse still for Labor, Shorten’s admission diminishes what would otherwise be a potent field of fire – Abbott’s own economy with the truth. Not only is there the repudiation of Abbott’s campaign commitments on health and education in last year’s budget, but also his admission in 2010 that he does not always tell the “gospel truth”.

His scripted remarks could be relied on, but Abbott confessed:

… in the heat of discussion you go a little bit further.

Put the two together and “trust” ought to be a fertile field of fire for the opposition. But this is improbable now – if not impossible – in light of Shorten’s confession and Labor’s record.

To make matters even more difficult for the opposition, Abbott is moving relentlessly to ensure other battlefields are “no-go zones” for Labor. It is already on a hiding to nothing over border protection, so why not let loose Immigration Minister Peter Dutton to conflate that and national security to argue that, because Labor could not “control” Australia’s borders, the opposition is soft on national security?

Tabloid Tony is moving heaven and earth to ensure that Labor’s attempts not to have a tissue paper between it and the government on national security still leave Shorten vulnerable. Throughout the debate on proposals to strip dual nationals involved in terrorism of their Australian citizenship, Abbott strived to portray Labor as more concerned about legal rights than community safety.

Even though his own cabinet forced Abbott to a position which the opposition could endorse, Labor still suffered damage on the way through. The government manipulated the timing of the parliamentary debate to make it difficult for Shorten to offer definitive support because for weeks there was no legislation on the table to consider.

It was another sign of Labor’s phobia that its attack on the government – such as it was – was largely confined to the cabinet split, rather than the substance of the disagreement. It is an irony that the cabinet dissenters saved Shorten from the full extent of the damage Abbott would have liked to inflict.

Nevertheless, Abbott’s intent is clear. And the opposition could not be accused of fighting fire with fire.

It is a legitimate question why, within weeks of the terrorist threat being lifted because of the risk posed by Islamic State, a letter from Martin Place gunman Man Monis to Attorney-General George Brandis talking about contacting the organisation did not raise a red flag. That the relevant authorities say there was nothing untoward in the handling of the letter invites the Mandy Rice-Davies riposte:

He would say that wouldn’t he?

Labor has been equally lead-footed on the budget. It was outmanoeuvred by the Greens on a more equitable-than-not tightening of pension eligibility and probably got in only just ahead of Greens leader Richard Di Natale on the re-introduction of fuel indexation.

Without the party rules Rudd introduced to make leadership coups close to impossible, other Labor powerbrokers might be lying to journalists right now about where they stand. And in July, there is Labor’s national conference for Shorten to survive, not to mention an awkward appearance at the royal commission into trade unions.