The government’s majority is at stake in the October 20 Wentworth byelection, when the Liberals face voters still reeling from the loss of their member Malcolm Turnbull.

ABC election analyst Antony Green says there’s likely to be a 10 per cent swing “as a start” - the result of losing Turnbull’s personal vote and a generally more intense battle. He says “the only danger” to the Liberals not winning the seat is high profile independent Kerryn Phelps but she may have made it harder for herself by “mucking up her preference comments earlier”.

Liberal candidate Dave Sharma recognises the public’s disappointment and disillusionment with politicians and if elected is keen to “help improve the tone of the debate in Canberra”. He accepts “absolutely” the science of man-made or anthropogenic climate change and believes in Australia “keeping our international commitments” on Paris.

Labor’s Tim Murray is “quite confident” he will finish second on the primary vote (although the ALP’s best chance of ousting the Liberals is to run third and help elect Phelps with its preferences). On the issue of asylum seekers, which has dogged his party, Murray says a Labor government should press for New Zealand to take more than its original offer of an annual 150: “Taking 300 would go a long way to resolving the problem of children being held in detention”.

Phelps says she has received a lot of thanks for putting her hand up for Wentworth but has also been subject to “dirty tricks”. Despite her confusing messages on preferences, she’s confident she can come second if enough “disaffected Liberals and people who agree with my progressive policy agenda are prepared to put their support behind [me].”

Michelle Grattan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.