Australia's conservative prime minister sounded the gun on the last lap of a bitterly-fought election campaign Sunday, admitting "not everything went to plan" during the country's pandemic response.

At an official launch of his party's election campaign ahead of the May 21 vote, conservative Scott Morrison acknowledged missteps during the crisis but declared "Australia has prevailed"

In reality, the election campaign has been underway for months -- if not years -- but the event offered Morrison a chance to rally the party base and appeal to voters who appear set to boot him out after three tumultuous years in office.

According to the latest opinion polls, the centre-left Labor party, led by Anthony Albanese is expected to win Saturday's vote.

But both sides know an upset is still possible.

Morrison's tenure has been beset by a rolling series of crises, from climate-fuelled droughts, bushfires and floods to the global Covid-19 pandemic.

"It has been one of the most challenging times we have ever known," Morrison said, while insisting the country was now "heading in the right direction."

Prime Minister Scott Morrison's tenure has been beset by a rolling series of crises, from climate-fuelled droughts, bushfires and floods to the global Covid-19 pandemic
Prime Minister Scott Morrison's tenure has been beset by a rolling series of crises, from climate-fuelled droughts, bushfires and floods to the global Covid-19 pandemic AFP / STR

The 54-year-old from Sydney's affluent Eastern Suburbs has come under fire for a glacial vaccine rollout that helped make sure Australia's borders were shut for the better part of two years.

He is also facing anger over the government's handling of natural disasters and reluctance to pivot away from fossil fuels.

Polls consistently show around 70 percent of Australians want more action on climate change, but Morrison has repeatedly rejected calls for ambitious climate targets or scaling back the country's vast coal mining industry.

Seeking to make the election a choice rather than a referendum on his leadership, Morrison has painted the Labor party as "loose units" on the economy and an Albanese premiership as an "experiment."

To sweeten the deal, Morrison also announced plans to allow first-time buyers to use their pension savings to purchase a home.

That policy is likely to be popular among young Australians struggling to get access to a turbocharged property market but is also likely to stoke home price inflation further.