With polls pointing to a potential Labor win at an election due by May, the prime minister on Friday marked his third visit to Liberal MP Melissa McIntosh's western Sydney seat of Lindsay in the past month.
It came a day after the delivery of the government's mid-year budget update.
"Jabs and jobs ... will continue to support us as which face down the pandemic," he told reporters at a Emu Plains manufacturing plant.
The seat is held on a slim five per cent margin and is at the centre of pork-barrelling allegations after a Nine newspaper analysis revealed the electorate received more than $23 million in grants over the past three years.
Three adjacent Labor seats received a combined total of just over $6 million.
Lindsay was also promised three car parks worth $55 million under the controversial congestion busting scheme, while none were offered to the three neighbouring Labor electorates.
It was the only NSW seat the Liberals managed to flip from Labor at the 2019 election.
Local veteran firefighter Trevor Ross will contest the seat for Labor at the 2022 election.
Speaking in the Queensland regional city of Bundaberg, Labor leader Anthony Albanese said Mr Morrison had a poor record on the handling of the pandemic.
"He can't afford to botch the supply of boosters," Mr Albanese said.
"They've announced changes to booster shot eligibility without worrying about how it will be delivered. It is something that characterises this government which is all about announcement and not delivery."
The continued blitz of marginal seats by the two leaders comes as the possibility of a March election remains alive after a better-than-expected mid-year economic and budget update.
The budget update released on Thursday predicted strong growth ahead and one million additional jobs, after a sharp fall in the unemployment rate.
The national jobless rate for November came in at 4.6 per cent on Thursday, down from 5.2 per cent in October.
The update, coupled with a $16 billion war chest of "decisions taken but not announced", may remove the need for the government to present its scheduled pre-election budget for 2022/23 on March 29.
It has the ability to make big-ticket announcements in January and February, paving the way for a possible election in March rather than May.
The government also announced the details of a free trade deal with the United Kingdom, with Trade Minister Dan Tehan saying the comprehensive deal would continue to grow investment across the board and provide a pathway to economic recovery from the pandemic.
But Labor finance spokesperson Katy Gallagher said the economic recovery was happening in spite of the government's management, not because of it, adding delayed COVID-19 vaccine rollouts and quarantine failures had led to extended lockdowns and economic damage.