Polls open in Australia "Super Saturday" by-elections

[SYDNEY] Australia's political leaders made last-gasp bids to sway voters Saturday as polls opened in five by-elections that could see the conservative government boost its wafer-thin parliamentary majority.

The seats are being contested following a string of forced resignations in the opposition Labor party after the High Court reaffirmed an obscure provision in the 1901 constitution that bars dual citizens from elected office.

Picking up just one of them will double Prime Minister Malcolm Turnbull's parliamentary majority to two.

The outcome is also being seen as a barometer on Mr Turnbull's re-election prospects and whether opposition Labor leader Bill Shorten should potentially be replaced ahead of national polls due by May next year.

Half a million people are eligible to vote.

Two of the five seats are considered Labor strongholds while another looks likely to remain with the independent Centre Alliance.

The others - Longman in Queensland state and Braddon in Tasmania state - are too close to call, although an opinion poll in Saturday's The Australian newspaper suggested Labor could cling on.

Should Mr Turnbull's Liberal coalition win a seat, it would be the first time a government has clinched one from the opposition at a by-election in 98 years.

Mr Turnbull has framed the polls as a referendum on the government's "jobs and growth" agenda while Labor is campaigning on better health funding.

"All of our candidates are standing for stronger economic growth, lower taxes, more jobs, higher wages, guaranteed funding for essential services that comes from a stronger economy," Mr Turnbull said during a final pitch in Braddon.

"Labor is a threat to all of that."

"We're saying to Australians voting today; don't put your essential services at risk. Don't put your jobs at risk. Don't put stronger economic growth at risk."

While the government continues to trail Labor in opinion polls, the deficit has been narrowing and Mr Shorten's personal popularity has been waning.

"I accept that when these campaigns started, Labor was the underdog in both Braddon and Longman. But Labor never gives up," said Mr Shorten, also campaigning in Braddon.

"The critical question to ask yourself when you cast your vote in these by-elections, is whether or not you want more of the same? Or do you want to see this government do better?

"Do you want to see better for our hospitals and schools? Better for our wages? Or do you just want to see more tax cuts for the top end of town?"

AFP