The Turnbull government has recorded its 80th consecutive loss in the Guardian Essential poll and the prime minister has shaved 17 points off his personal approval rating since his honeymoon period at the end of 2015.

Labor remains ahead of the Coalition in the latest fortnightly opinion survey on the two-party preferred measure 53% to 47%, similar to this week’s milestone negative Newspoll result, which was 52% to 48%.

While the trend is stubbornly negative, Malcolm Turnbull remains comfortably ahead of Bill Shorten on Guardian Essential’s preferred prime minister measure. Turnbull leads 41% to the Labor leader’s 26%.

At the end of 2015, back when Turnbull took the Liberal leadership from Tony Abbott, the margin was more commanding. He led Shorten as preferred prime minister 54% to 15%.

If we chart movements in the poll series from December 2015 to the present, we can chart Turnbull’s decline in the top job.

Turnbull’s personal approval shortly after he took the Liberal leadership from Abbott was 56% and his disapproval 23%. Roll forward to this week and Turnbull gets the thumbs up from 39% of the sample and the thumbs down from 42%.

Measured over the same timeframe, Shorten secured approval from 27% of the Guardian Essential sample in December 2015 and 47% disapproval. This week, the Labor leader’s approval stood at 35% and his disapproval at 43%.

In news that will comfort the prime minister, Turnbull remains the pick of voters as preferred Liberal leader, with 24% (up 3% since December) nominating him. Julie Bishop is seven points behind that on 17% (down 2%) and Peter Dutton rates only 3%.

Tony Abbott is favoured by 11% of the sample of all voters (up 1%) but, underscoring general voter disaffection, 27% do not know who they want to lead the party of government, and 14% say they want “someone else”.

Turnbull also remains the favoured option of Coalition voters, with 45% support, which is up 5% since last December. Bishop over the same period has gone backwards with the base, preferred by 13%, down 7%, while Abbott has had a small resurgence, with 17%, up 4%, nominating him.

When you take Turnbull out of the picture, 26% of the sample nominates Bishop as the best leader of the Liberal party, while 16% say Abbott, with Dutton creeping up to 5%. Among Coalition voters, 30% prefer Bishop, 26% Abbott and 8% Dutton.

Among Liberal/National voters, 30% prefer Bishop, 26% prefer Abbott, with Dutton the outlier at 8%.

Voters were asked questions this week about the attributes of the major party leaders. Compared with the Labor leader, Turnbull is more likely to be considered intelligent (+15), out of touch with ordinary people (+13), a capable leader (+9), arrogant (+8) and good in a crisis (+7).

Voters nominated Shorten’s key attributes as hard-working (60%, up 1% since last June), intelligent (59%, up 1%), out of touch with ordinary people (50%, up 3%) and understands the problems facing Australia (47%, down 1%).

Turnbull’s key attributes were intelligent (74%, up 2%), out of touch with ordinary people (63% down 2%), hard-working (60% plus 1%), a capable leader (53% up 3%), arrogant (51% down 4%) and superficial (51% down 1%).

Opinion polls this week have assumed greater than normal significance because Turnbull has now notched up 30 consecutive negative Newspolls – which was one of benchmarks he used to oust Abbott from the top job.

Turnbull says he now regrets ever having invoked the poll as a rationale for a leadership spill and contends he has delivered on the other elements he promised to address in 2015, such as restoring a properly functioning cabinet government and stronger economic management.

The milestone on Monday prompted a full court press in defence of the prime minister, with cabinet ministers lining up to say there was no threat to his leadership.

But while colleagues have rallied in support, Abbott’s insurgency remains in plain sight, Dutton has made it plain he has prime ministerial ambitions and the treasurer, Scott Morrison, also said on Monday night he would put his hand up in the event the leadership ever became available.

The Guardian Essential poll currently has Morrison favoured as Liberal leader by only 2% of the sample, and 5% excluding Turnbull from the list.