Australian Prime Minister Scott Morrison has extended his lead as the country's most preferred leader, a poll showed on Monday, boosted by his government's coronavirus wage subsidy scheme and efforts to contain the spread of the pandemic.

A Newspoll conducted for The Australian newspaper showed Morrison enjoyed the best approval rating over an opposition leader in more than five years.

Morrison's popularity fell over his handling of bush fires late last year but he has improved his standing with his response to the pandemic, as the country battles a new wave of infections in Victoria state.

Morrison jettisoned his conservative government's aversion to deficits to pledge spending worth about 100 billion Australian dollars (71.50 billion U.S. dollars) to employers to keep staff they might otherwise have let go.

The government last week eased rules to qualify for its wage subsidy scheme as a flare-up in infections in Victoria forced large parts of the economy to close.

With just over 21,400 infections and 314 deaths from the virus, Australia has fared better than many other developed nations, helped by strict lockdowns that are expected to push unemployment up towards 10 percent.

Australia's central bank downgraded its outlook for the national economy on Friday and warned unemployment would stay high for several years.

Morrison's approval ratings remained at a high of 68 percent against a two-point rise among those dissatisfied with his performance, the poll showed.

The poll was based on surveys of just over 1,500 voters across the capital city of Canberra and other regions from Wednesday to Saturday.

Morrison said internal border closures were unlikely to lift before Christmas, as the country on Monday reported a record single day rise in COVID-19 deaths.

There was, however, some evidence that drastic lockdown measures in the city of Melbourne were having an effect, with daily new infections in the state of Victoria slowing to a near two week low.

Victoria state, which is home to Melbourne, the country's second biggest city and the epicenter of its second coronavirus wave, reported 19 people had died from the virus over the past 24 hours. With some other states still to report daily new case and death numbers, that already marks the country's biggest single day rise in fatalities.

Australia's most populous state, New South Wales, reported 14 new cases, and no deaths, on Monday, while authorities worry the spike in cases in Victoria has already spread to other states despite borders border closures.