It seems likely that Malcolm Turnbull will call an early election for August 2018. While losing 30 Newspolls in a row, the gap is not large and could easily be closed. In fact, the recent Fairfax IPSOS Poll has the two party preferred vote close to even – depending on how preferences are allocated.
The Turnbull government has made it clear that there will be personal tax cuts in the May 2018 budget. This will make some voters more happy and will tend to boost the economy. Employment growth has been very strong, but seems to be weakening (growth has been temporarily boosted by the National Disability Insurance Scheme rollout). A tax cut fillip may just extend the good employment news for another few months. Good old Keynesian fiscal stimulus
Today Malcolm Turnbull announced $5 billion to build the airport to city rail link we have been waiting for these last 50 years. The funding has to be matched by the Victorian State government who face the polls in November 2018. How can they refuse?
Today there are reports that Malcolm has asked the party machine to have all pre-selections finalised soon.
The timing of the federal election is constrained by the timing of state elections in Victoria (November 2018) and New South Wales (March 2019) and by the need to have a half Senate election within the next 12 months.
Prime Ministers tend to call elections when they expect the economic news to be best and that will probably be in August 2018.
On the subject of political opinion polls, they are becoming less accurate. See my article in my book Forecasting: the essential skills.