Part ground game, part mind game.

Surrounded by adorable Labrador puppies (in training to become guide dogs) in Melbourne on Saturday morning, Bill Shorten unleashed his inner Rottweiler when he introduced Labor's candidate for the "marginal" seat of Kooyong.

Only it's not marginal.

Kooyong is held by Josh Frydenberg on what would normally be considered a healthy 12.8 per cent margin.

But the Treasurer is facing a serious challenge from a former-Liberal-turned-independent and a high-profile Greens candidate who could snatch the seat or hand it to Labor with their preferences, in a progressive state that punished the Liberals in last year's state election.

Mr Shorten joked it was the first time he had visited Kooyong during an election campaign, demonstrating his level of confidence a week out from polling day.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 7 minutes 31 seconds 7 m Josh Frydenberg faces some high-profile challengers in the seat of Kooyong

The Victorian malaise

His hour-long stopover to Kooyong would have been noted by the Treasurer, who is sensitive to the fact that his blue-ribbon seat is under threat.

The fourth week of the campaign has been defined by the two leaders' offensive and defensive strategies.

Prime Minister Scott Morrison has almost exclusively focused on sandbagging Coalition-held seats (even ones on big margins like Farrer at 20.5 per cent and Cowper at 12.6 per cent).

On Saturday he was campaigning in Deakin — his second visit to Liberal Michael Sukkar's seat, which is not considered marginal but is suffering from the Victorian malaise of disenchantment with the Coalition.

The Prime Minister was in Deakin offering Michael Sukkar support against the Victorian disenchantment with the Coalition. ( AAP: Mick Tsikas )

The Labor leader has been on the attack — Kooyong on Saturday, Leichhardt, Petrie and Bonner in Queensland earlier in the week. None of them held by the ALP but all in Labor's sights.

Labor went into this race on a notional 72 seats after a redistribution handed it three Liberal electorates. That leaves it just four shy of government and it has targets in every state.

In the words of one Labor strategist: "Our path to victory is a freeway, theirs is a goat track."

A conservative path to victory for Labor lies in picking up Dunkley and Chisholm in Victoria, Swan, Hasluck and even Stirling in the West, possibly Boothby in South Australia, Reid and Gilmore in New South Wales and Petrie and Flynn in Queensland.

But there is a real sense that it could be much larger than that, particularly after the last week, which saw strong performances by the Labor leader on the ABC's Q&A program, Press Club debate and of course his emotional response to the Daily Telegraph's report on his mother.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 2 minutes 37 seconds 2 m 37 s State political reporter Richard Willingham on why Victoria will matter this election

Labor's final strategy

The Labor leader will today make a $10 billion pitch to Victorian voters, promising to part-fund Melbourne's suburban rail loop, in what is expected to be one of the last major commitments of the campaign.

Its policies have been outlined, much-anticipated costings released and from here, it is all about selling the message and managing risk.

Most of Mr Shorten's recent campaign events have been pared down to highly stage-managed encounters, away from the higher-risk street walks and big shopping centre visits where a single angry voter could become the opening picture of the nightly news.

His minders will be keen to ensure the awkward handshake with workers at the Brisbane Port is not repeated, sticking to low-risk events like a tour through the Cairns Aquarium or a visit to a Guide Dog training centre in Melbourne.

These last days though are not without risk and that is the reason for the nervousness. The Labor leader has agreed to interviews on Insiders and 7.30 — notoriously tough formats — and he is considering a Press Club address, as is tradition for both leaders in the last week of the campaign.

While the opinion polls have consistently pointed to a Labor win, sources say the results in the NSW and Victorian elections suggest a large chunk of voters will not make up their minds until final week or election day.

At this stage of the race, the hope in Mr Shorten's heart, and the fear he wants to implant in the Government's mind, is that the Coalition's castle walls will fall and deliver Labor an epic victory.