By Matt Siegel
SYDNEY (Reuters) - Australia's ruling Liberal-National coalition is leading its Labor opposition for the first time in 16 months after former prime minister Tony Abbott was toppled by Malcolm Turnbull in a party-room coup four days ago, an opinion poll showed on Friday.
Turnbull's Liberal Party and its junior coalition partner the Nationals won a landslide election in 2013 but Abbott was jettisoned on Monday after a series of policy missteps and destabilizing infighting.
The poll will be studied closely for implications that the decision to install Turnbull, a Rhodes Scholar and former investment banker, has reversed the government's sagging fortunes ahead of an election due in about a year.
The poll by Galaxy Research noted a three-point bounce in the government's primary vote since its previous poll in May, from 41 to 44 percent.
On a two-party preferred basis - the most significant indicator where votes for minor parties are redistributed to the two main blocs according to preferences - the government is also leading the center-left Labor Party by a margin of 51-49.
The poll of 1,224 voters, conducted after the change of leaders on Monday, also had 51 percent of respondents rating Turnbull as their preferred prime minister, compared with just 20 percent for Labor leader Bill Shorten.
A string of dismal polls showed a likely rout for the government at the elections due by the end of next year if it stuck with Abbott.
Abbott ousted Turnbull as leader of the Liberal Party in opposition in 2009, although Turnbull has consistently been seen as a preferred prime minister by the public.
Turnbull's support for a carbon trading scheme, gay marriage and an Australian republic had made him unpopular with his party's right wing, and he has pledged not to reverse course on those issues in an effort to unite the fractured party.
The leadership reshuffle came as Australia's $1.5 trillion economy struggles to cope with the end of a once-in-a-century mining boom. It was also less than a week before a by-election in Western Australia state that was widely seen as a test of Abbott's leadership.
A Fairfax-Ipsos poll published on Monday, before the leadership change, showed voters in the Western Australian seat of Canning delivering a swing of up to 10 percent against the government in Saturday's by-election.
Party infighting has resulted in four changes of leaders in the past two years in Australia, political instability that has shaken public and business confidence in government.
(Editing by Paul Tait)