Australian election polls show race tightening in final campaign stretch as the ruling conservative coalition narrowed the gap with the main opposition Labor Party

Australia's national election has become too close to call, polls out on Wednesday showed, as the ruling conservative coalition narrowed the gap with the main opposition Labor Party, three days before the country decides on a new government.

Centre-left Labor's lead over the Liberal-National coalition has shrunk to 51-49% on a two-party preferred basis from 54-46% two weeks ago, a poll done for the Sydney Morning Herald showed. A Guardian poll indicated Labor's lead had dipped to 48-46% from 49%-45% two weeks ago.

Prime Minister Scott Morrison described the pre-polling trends as "really encouraging", while Labor acknowledged the election would be "incredibly close".

With Australia going to the polls on Saturday, rising living costs have dominated the final stretches of the campaign with voters rating it as the most critical issue in some polls.

Australian wage growth ticked up by only a fraction last quarter, data out on Wednesday showed, even as a tightening labour market and record vacancies heightened competition for workers.

But consumer price inflation has risen twice as fast as wages, keeping real income in the red.

"I have been very candid with Australians about the economic challenges we're facing ... Labor has no magic bullet on this, they have no magic pen or magic wand," Morrison told reporters from the marginal Labor-held seat of Corangamite in Victoria.

Opposition leader Anthony Albanese blamed government mismanagement for the slow rise in wages and inflation shock.

Nearly 6 million voters out of an electorate of 17 million have already cast their ballots through postal votes or early in-person voting, official data showed.