Australia’s Prime Minister-elect risks becoming a victim of his own success following an emphatic election win that threatens to reopen splits within his conservative coalition.

Tony Abbott and the Liberal-National Party coalition surged to victory late on Saturday with a disciplined election campaign that painted a contrast to the country’s three tumultuous years under the Labour Party, with its revolving-door leadership of Kevin Rudd and Julia Gillard.

With preliminary counting complete, election officials projected Abbott’s coalition would win at least 88 seats in the 150-seat Parliament. It could end up with a 30-seat majority.

But ironically, the decisive win could ensure a short honeymoon and uncover long-standing fissures within what until now has been an unusually unified bloc.

One of Abbott’s centrepiece promises of a paid parental leave scheme is unpopular with business backers and within his party, and there are simmering tensions over Chinese farm buying, labour reform and overseas investment.

Economist and former central bank board member Bob Gregory says Abbott will face pressure from both restless backbenchers and fundamentalist reformers who believe that, with a big win, Abbott has a mandate and a responsibility to reform.

“What it will do is strengthen the right, and the right will say, well the economy is not doing it, we’ve got the mandate, and if we don’t do it, what are we here for?’ It’s all going to be harder for him to control having won.”

Shellshocked by the protracted farce of Labour’s leadership implosion and nervous of the economy’s retreat from the peaks of a China-led boom, a majority of Australia’s 15 million voters have put their faith in Abbott.

Decisive win could uncover long-standing fissures

But it is unclear how convinced some on his own side of politics are, with rumblings over the fiscal rectitude of policies that paved Abbott’s victory, including a $4.3 billion (€3.3 billion) paid parental leave scheme underpinned by a levy on 3,000 big companies.

The differences were briefly bared early in the campaign when Liberal backbench MP Alex Hawke said business leaders – a key conservative support base – believed the scheme was unaffordable and incompatible with a centre-right philosophy on small government and economic liberalism.

Hawke was rapidly silenced by Abbott’s senior lieutenants.

“From time to time you are allowed to make a captain’s call,” Abbott said in explaining why he had pushed his plan.

“But you can’t do it very often, because quite soon your colleagues think that you’re abusing your position.”

The centre-right is a sometimes fractious coalition of rural-based Nationals and city-based Liberals, with differing views on regional support in a vast continent of 23 million and where eight in 10 people live in just a handful of cities.

Divisions exist also between the liberal and conservative wings of Abbott’s own Liberal Party, split over the extent of government intervention in the $1.5 trillion (€1.2 trillion) economy and welfare, as well as social platforms like detention of overseas asylum seekers.