SYDNEY (REUTERS) - Australia's conservative government is heading for defeat in a looming election, a widely watched opinion poll showed on Monday (March 11), after disappointing news on the economy tarnished the credibility of Prime Minister Scott Morrison.

Notching its 50th poll loss in a row, the Liberal-National coalition trailed the centre-left Labor Party by 54 per cent to 46 per cent on a two-party preferred basis.

The coalition trailed Labor by 53 per cent to 47 per cent in the previous Newspoll for The Australian newspaper.

The results would give Labor a clear victory if the election were fought today. Time is short, as the vote is expected some time in May.

The coalition's primary vote was on 36 per cent, behind Labor on 39 per cent. The poll of 1,610 people was conducted from last Thursday to Sunday and had a margin of error of 2.4 percentage points.

The result comes a week after government figures showed the Australian economy almost ground to a halt in the fourth quarter of last year, undermining the coalition's claim to being the party of better economic management.

The coalition has also been hit by a wave of high-profile retirements, with two senior ministers saying earlier this month they would not contest the election.

Mr Morrison needs to retain all the parliamentary seats held by his coalition government, but his chances are weakened by a wave of incumbent lawmakers in marginal seats set to retire.

The government has its annual Budget on April 2 and is expected to announce a return to surplus and likely some sort of tax cuts or spending promises to sweeten voters.

Monday's poll did show Mr Morrison remained the preferred prime minister over Labor's Bill Shorten, with a share of 43 per cent to 36 per cent.

Some 43 per cent of voters approved of Mr Morrison's performance, while 45 per cent disapproved.

The findings come despite Mr Morrison's attempt to cast the election as a referendum on border security and asylum-seekers, hot-button topics in previous votes.