New poll predicts Allegra Spender will win Wentworth from Liberal MP Dave Sharma

Spender, who is backed by Climate 200 and is running on a platform of action on climate change and integrity in politics, has recorded a 33.3% primary vote and is now enjoying high recognition.

But it will be preference flows that determine the final outcome, and Spender has a much more certain flow of preferences.

Sharma is expected to pick up preferences from the 5.3% of United Australia party voters whose how-to-vote cards put Sharma ahead of Spender. But, surprisingly, only 30% said they would give their preference to Sharma, with 40% unsure who they would preference. Spender would pick up 30% of these preferences.

The single-seat poll was conducted by Redbridge Polling on behalf of the Spender campaign in the first week of May and involved automated calls to 1,117 people in the seat. It has a margin of error of 3.7%.

The pollsters did not attempt a two-party-preferred calculation, but a look at the 2019 election result reveals the dilemma for Sharma.

In 2019 Sharma won 47.4% of the primary vote but only narrowly won the seat with 51.3% two party preferred, with most of the preferences from Labor and Greens eventually ending up with the independent Kerryn Phelps.

There is also now a very low undecided vote in Wentworth of just 4.4%, indicating that most people have made up their minds.

There has been much discussion about the accuracy of single-seat polls because of the difficulty of assembling a database of phone numbers within the seat and adjusting for specific demographics. Redbridge said it had polled a mix of mobiles ( 75%) and landlines (25%) between 5.30pm and 8.30pm on weekdays and between 10am and 5.30 on Saturday to ensure it did not oversample non-workers and stay-at-home people.

The poll reveals that Wentworth voters are less motivated by issues of economic management and cost of living than other parts of the country. More than 27% nominated climate change and the environment as the most important issue, followed by 22% nominating the economy, 17.4% integrity and trust in politics, and 8.8% cost of living.

Among 18 to 39-year olds, cost of living loomed larger as the decisive issue but climate change was still the No 1 issue across all age groups.

Among voters over 60, the economy, national security, and health and aged care were more important, with 25% of the age group nominating the economy as most important in deciding their vote.

It found that Labor would win a majority government with a modest 80 seats, but predicted that Spender would lose Wentworth, with Sharma returned on an increased margin (56%-44%).

The Redbridge polling is at odds with the YouGov Wentworth finding and will become something of a test case of polling methods.

If preferences were allocated based on historical flows, Labor would have a narrow win, 51-49%. But when people were asked how they intended to allocate their preferences, Labor would win 54-46%.

The poll also asked some specific questions. Some 92% of Higgins voters support truth in political advertising law, while 52% of Higgins voters oppose new coal and gas projects, with only 31.5% in favour.