By Colin Packham
SYDNEY (Reuters) - Australia's government hit a six-month low in a widely-watched opinion poll on Monday, with Prime Minister Malcolm Turnbull's one-seat majority in jeopardy over a citizenship crisis which could see three cabinet ministers thrown out of parliament.
Australia's parliament has been rocked by the revelation that seven politicians, including three ministers, are dual citizens, potentially ruling them ineligible to hold elected office.
Turnbull's center-right coalition government trails the opposition Labor party by a margin of 54-46, a Newspoll for the Australian newspaper showed, the lowest since February 2017 when support for Turnbull hit its lowest level.
At the same time support for the far-right One Nation party jumped two points. One Nation leader Senator Pauline Hanson drew political rebuke last week when she wore a burqa in parliament as part of a campaign to ban the burqa on security grounds.
The next national election is not due until 2019, but continued poor polling may entice a leadership challenge to Turnbull, says political analysts.
"Voters seem to have made up their mind that this government under Turnbull is not effective. The only way he can turn it around is to get the citizenship issue out of the way quickly," said Haydon Manning, a political science professor at Flinders University in South Australia.
The High Court of Australia will this week set out a timetable for ruling on the eligibility of the seven politicians under a citizenship cloud.
A 116-year-old law demands an elected lawmaker only have Australian citizenship, but some have discovered they hold dual citizenship by descent of a father being born in another country, such as neighboring New Zealand.
Australian Attorney-General George Brandis said on Sunday said a final decision was unlikely before mid-October.
Labor leader Bill Shorten called on the High Court to disqualify the seven politicians.
"The constitution needs to be upheld and honored," Shorten told reporters in Sydney.
(Reporting by Colin Packham; Editing by Michael Perry)