(This version of the Jan 9th story corrects spelling of minister's first name to Sussan, paragraph 2)
By Tom Westbrook
SYDNEY (Reuters) - Australia's health minister stepped down temporarily on Monday to allow auditors to scour her expense accounts after she bought an investment apartment while on a work trip, an embarrassing start to the year for embattled Prime Minister Malcolm Turnbull.
Health Minister Sussan Ley's spending inquiry follows a 2015 expenses scandal where a government MP was unseated after billing taxpayers for a helicopter flight and comes with Turnbull languishing in polls and facing a restive party room.
A Newspoll in Monday's Australian newspaper put Liberal prime minister Turnbull and his opposition Labor counterpart Bill Shorten as the least popular pair of national political leaders in 20 years.
In the year to come Turnbull's Liberal Party-led government faces a fractious Senate that has so far stymied major progress on its legislative agenda, mainly focused on spending cuts and tax reforms aimed at balancing the national budget.
Turnbull has also struggled to keep the support of the hard-right of his own party, which still simmers with resentment since he toppled the more conservative Tony Abbott as prime minister in a party-room coup in 2015.
Ley, who is also aged care minister and sport minister, has been fighting calls for her resignation since Friday when it was revealed she made expense claims for several visits to the Gold Coast, a holiday destination in Queensland state, including one when she said she purchased an investment property on impulse.
Ley said she had agreed to stand aside after a discussion with Turnbull and had agreed to repay some claims for transport and accommodation on one Gold Coast trip, some 1,300km (800 miles) from her electorate, when she purchased the apartment.
"I apologise for the distraction that this issue has caused," she told reporters. "I'm very confident that the investigation will show that I have not broken any of the rules."
Turnbull's government has also come under pressure in recent weeks for a heavy-handed approach to recouping social security debts. Opposition politicians say an automated debt-collection system has miscalculated welfare entitlements and wrongly demanded repayments from many recipients.
But the government says the system is working and could recoup as much as A$4 billion ($2.9 billion) in taxpayer money.
(Reporting by Tom Westbrook; Editing by Jane Wardell and Michael Perry)