The Labor party has taken “all of the wrong lessons” from its election loss and is morphing into a facsimile of the Coalition, Richard Di Natale says, as a former Labor senator urged the party not to engage in an orgy of revisionism.

In a speech to party faithful at the Greens national conference in Adelaide later on Saturday, Di Natale will say that he had hoped “finally putting the last six years of turmoil and division behind us” but instead faced “an embolden conservative government”.

“[A government] stacked with climate deniers and hellbent on taking us down the US path with a permanent underclass of working poor, obscene wealth in the hands of a tiny and powerful few and, a worldview that sees our natural world as something to exploit for corporate greed rather than protect for future generations,” he says.

But he saves some of his strongest criticism for the Australian Labor party, who he accuses of abandoning its ideals.

“Even worse, they’re being helped by a Labor party that seems to be taking all of the wrong lessons from the election and think that the way to defeat the tories is by becoming just like them,” Di Natale will say.

“In the past few weeks they’ve turned their back on 100 years of support for progressive taxation and voted with the Coalition to gut our tax system, open up the Galilee basin to more coal mining and refusing to increase Newstart.”

Di Natale’s latest salvo comes as Doug Cameron a warrior for the Labor left who retired from the Senate at the last election, used a speech at his farewell dinner late last week, to urge Labor to stay the course with the policy agenda it spent six years building.

Cameron told the room, which included Albanese and other leading Labor figures, to avoid a Tony Blair-style Labour government or thinking it could win over the electorate by “masquerading as a pale imitation of the Coalition”.

The relationship between the Greens and Labor has become increasingly fraught as they tussle for ownership of progressive issues such as climate change, income inequality and social justice, often vying for the same voting pool.

Earlier this week, Albanese criticised the Greens for stunt motions in the Senate, which he said were “usually aimed at … putting out a media release bagging the Labor party” and he wanted to see Labor defined for what it stood for, rather than what it was against.

“The Greens have forgotten that the Coalition’s in government and are obsessed by attacking Labor,” he said on Tuesday.

“That’s up to them. But the fact is, that were we successful on the 18th of May, we would have had an inquiry into the rate of Newstart. That was not an inquiry so that we could lower it. That was an inquiry obviously so that we could look at what an appropriate level is.”

Labor has begun its review process of what went wrong in the 2019 campaign, after it lost an election it was widely expected to win, after which it will finalise its position on inequality levelling policies including negative gearing and franking credits.

Cameron advised the party to hold the line.

“I’ve said on many occasions, that I had never felt more comfortable with Labor party policy than with the policies we took to the last election,” he said.

“… We must properly analyse why such a progressive and beneficial policy agenda for working class Australians failed to deliver government to the ALP.

“We must not engage in an orgy of revisionism. We must never abandon a progressive agenda for Australia. We must resist pressure to move to the middle ground of politics.

“We cannot win government masquerading as a pale imitation of the Coalition or as a ‘third way’ Blairite clone.

“We must never abandon the historic struggles and principles of a forward thinking Labor party.”

Cameron also used his speech to urge caution against waving through changes to national security without consideration of who watches the watchers, his advice arriving just days before the parliament considers Peter Dutton’s latest requests for further security powers.

“No one from the left should forget the role that these agencies play in serving conservative governments by engaging in covert surveillance, infiltration and political attacks on left wing Australians,” he said.

“We should learn from the lessons of the past and make sure that if we support increased powers for security agencies that increased checks and balances are in place. We need proper parliamentary oversight and the capacity to ensure that security agencies are acting in the national interest.

“… Our existing oversight is inferior and in my view, almost non-existent. This is unacceptable and we should ensure our inferior parliamentary oversight of security agencies is changed and oversight enhanced.”