Opposition Leader Bill Shorten has extended his lead as preferred prime minister over Tony Abbott as the government continues its post-budget polling slump, today’s Essential Report shows.

Having taken a one-point lead in May, Shorten now leads Abbott as preferred prime minister, 40%-36%, and has a bigger lead — 8 points — among women than among men (2 points). The Prime Minister’s disapproval rating has increased  from 55% to 58%, while his approval rating has remained on 35%. Shorten’s disapproval rating has also increased, from 37% to 40%, but so has his approval rating, from 35% to 38%.

The Coalition’s primary vote has also fallen a point to 37%, its lowest since January 2010, while Labor’s primary vote has reached 40%. The Greens are down a point to 9% and the Palmer United Party is steady on 6%, for a two-party preferred outcome of 54%-46% to Labor, its best since August 2010.

Essential also asked about perceptions of fairness and equality in Australia, revealing significant partisan differences among voters. Among Greens voters, 70% believe Australia is less fair and equal than 20 years ago; among “other” voters (including Palmer United Party), 59% believe we’re less fair and equal. Fifty-one per cent of Labor voters believe that, and 27% of Coalition voters.

Voters split differently on the importance of equality. Forty-one per cent of “other” voters and 42% of Coalition voters say equality is “very important” while 62% of Labor and 63% of Greens voters say it is very important. But fairness is more widely supported: 77% of Greens and “other” voters and 72% of Labor voters believe it is very important, and 44% of Coalition voters. The switch of “other” voters in that mix is interesting, suggesting they support the idea of equal opportunity suggested in “fairness” while being less interested in equal outcomes, which are more attractive to progressives.

The picture gets more complicated on measures that are viewed as important to equality. Greens voters nominate “access to affordable healthcare” (54%) and “a minimum wage that supports the basics of life” (53%). Coalition voters also nominate healthcare (53%) and minimum wage (49%) as most important — the latter higher than Labor voters (44%).

Labor voters instead see healthcare (69%) as far more important. Coalition voters also rate “well-resourced public schools” more highly than Labor voters, but don’t regard a strong welfare system as important compared to non-Coalition voters, instead seeing policies that encourage economic growth as being more important (38% compared to 20% of all voters).

Essential asked about attitudes toward United States drone strikes in the wake of revelations about the killing by the US of two Australian citizens in Yemen. Forty-five per cent of voters disapprove of drone strikes in general, compared to 35% who approve, although Coalition voters split the other way, 48%-33%. The overall result masks an enormous gender gap: men approve 47%-39% while women disapprove 51%-23%

And  58% of voters are concerned about the possibility of Australians being killed by drone strikes, with voters much more uniform in their concern, although women (63%) were more concerned than men (55%).