After refusing for weeks to support the Fair Work Commission’s recent ruling on weekend penalty rates, Prime Minister Malcolm Turnbull changed his tune on Friday, telling tabloid radio listeners that “of course” he supported the decision.

The PM’s admittedly belated willingness to own the FWC’s pro-business stance suggests he may have found his mojo again.

Of course, this discovery didn’t happen in a vacuum. It’s been a week of small wins and increased confidence for the embattled PM, which may deliver an increase in voter support this weekend when Newspoll again tests the political pulse of the nation.

Importantly for Mr Turnbull, those small wins were on big issues, at least as far as mainstream voters are concerned.

His announcement of a feasibility study into expanding the Snowy Hydro scheme captured the attention of the media, at least until South Australian Premier Jay Weatherill reminded us what a canny retail politician he is by high-jacking the headlines with a spectacular dummy spit.

Nevertheless, the PM had at least lodged a notion in voters’ minds that he had “a plan” to keep the lights on, which is a priority issue for most Australians. To make sure the point wasn’t lost, the PM reiterated it in an email to the party faithful on Friday, claiming the Snowy expansion “will mean cheaper power prices, fewer blackouts and more money in the pockets of Australians.”

At almost the same time the email from the PM had landed in supporters’ in-boxes, an electronic missive from Labor HQ went out to their true believers, offering a bumper sticker in exchange for a donation.

Claiming the PM wanted the penalty rates issue to “just go away”, the Labor email said a “sudden” pay cut to “700,000” workers was at stake – even though both these elements are disputed.

The duelling emails expose what the parties expect to be barbeque stoppers at the next federal election. Malcolm Turnbull is hoping his plan for “keeping the lights on” will also keep him in the Lodge, while Labor is confident it can turf him out by convincing voters the PM is refusing to stop threats to their jobs such as penalty rate cuts and foreign workers.

So it was risky for the PM to stand up for the penalty rate cut, yet his preparedness to do so on Friday suggests he’s judged the issue to be a two-edged sword for Labor due to the party’s association with its industrial wing, the union movement.

Unions have worked hard since the Royal Commission into their conduct to distance themselves from isolated incidences of corruption and thuggery. They’ve done so by repositioning their organisations in terms of union members that are highly-respected by the general public such as nurses, teachers and firefighters.

Turnbull said ACTU secretary Sally McManus supported breaking “unjust” laws. Photo: AAP

Yet it only took one frank comment from the new ACTU secretary, Sally McManus – confirming that she supported the breaking “unjust” laws – to show that perceptions of union “lawlessness” have become deeply entrenched since the Royal Commission, and that this will be exploited by the Government, the business sector and some sections of the media to undermine the Labor Party, by association.

Ms McManus could have nuanced her words, but that would not have sat well with her fellow unionists, who are aiming to motivate and recruit voters bristling for a fight with the Liberals at the next federal election.

In any event, it should have been a statement of the bleeding obvious. However, the union leader’s fightin’ words appear to have been taken by Malcolm Turnbull as permission to enter the fray on penalty rates.

Having spied a weakness in Labor’s flank, the PM prodded further on Friday, not only supporting the penalty rates cut but claiming Ms McManus’s comments proved unions considered themselves “above the law”, that this meant he could not work with work with her, and that “These are the people … [and] lack of values that is driving Bill Shorten – so he doesn’t care about the truth and he doesn’t believe in the law.”

In case voters still hadn’t made the connection, Liberal Party HQ then followed up with yet another email containing a link to this unsubtle Facebook ad.

However, Mr Shorten’s response suggests the PM’s instincts on this could be correct.

Having been wedged between supporting the rule of law or the union movement, Mr Shorten is reported as having taken the high road. “I just don’t agree,” the Opposition leader said. “We believe in changing bad laws, not breaking them.”