You wouldn’t believe it. Just four days out from the election the Coalition has found $2.3bn from yet another “crackdown” on welfare recipients and pensioners that more than pays for all the pork barrelling it’s been doing for the past eight weeks.

Every CCTV camera, road, football stadium and netball court showered upon Coalition marginal seats can be funded from cracking down, again, on overpayments, waste and, in some cases, rorting, which were already cracked down upon with such determination last year that it was forecast to yield $3.7bn. That’s a lazy $6bn in waste and abuse.

The Department of Finance “signed off” on the latest $2.3bn before the election, which does raise the question as to why it wasn’t included in the budget in May. If it had been in the budget it would have been the government’s second-biggest saving.

The government says it’s all about data matching and data analytics – recovering debt from people who were inadvertently overpaid, or who have made mistakes, or who in some cases have been abusing the system.

But the peak welfare group, the Australian Council of Social Service, is worried – not that the government is trying to recover what is owed, but that the aggressive debt recovery of inadvertent overpayments will target people living on so little, and that the promised automation could remove human discretion from the process.

And National Seniors says one reason older Australians might not be across the system is that in 2013-14, 29% of them had to wait more than 30 minutes on hold before they could even talk to someone at Centrelink.

Either way, suddenly retrieving the savings from the back of the couch at this point in the campaign makes proper scrutiny very difficult.

It doesn’t serve the interests of the people about to be affected by the changes, but it did serve the Coalition’s broader political point – to extend just a little further the gap between its projected deficits and those of Labor – cue Scott Morrison’s message about Labor being a threat to the economy.

On the other side of politics, Bill Shorten was making his final campaign pitch at the National Press Club.

It was a strong speech, framing Labor’s economic argument in the context of Brexit, arguing that Labor’s policies are far better placed to avoid the inequality and social division that fuelled the disillusionment and anger behind the Brexit vote. Cue Labor’s message about the need to reduce inequality, retain Australia’s social compact and not cut payments to the lowest-income families or erode the revenue base with corporate tax cuts.

But then Bill Shorten tried a grand finale – a “gaffe” that he said “marked the end of the prime minister’s credibility”. (Labor was so excited, it had already turned the alleged gaffe into an ad.)

Shorten quoted Turnbull saying that “what political parties say they will support and oppose at one time is not necessarily what they do”. It was, Shorten insisted, the defining moment of the campaign, proving the prime minister would be prepared to lie.

Except Turnbull had been talking about several policy reversals the Labor party has made in recent days – Coalition policies they have railed against for years but have now quietly accepted.

Sneaky tactics keep trumping credible arguments in this election.