John Grimes accuses environment minister of threatening him with negative media coverage if he did not drop campaign

A row between Greg Hunt and the chief executive of the Australian Solar Council has flared, with the renewable energy advocate accusing the minister of threatening him with negative media coverage if he did not desist from a campaign against the government.

John Grimes said the federal environment minister called him to “warn him off” a campaign that would target marginal electorates across Australia before the next election.

Grimes told the ABC that Hunt threatened a “pointed, public attack on me and my character” if he did not shut down the campaign. Hunt dismissed the allegation as “patently false”.

Grimes has promised to continue the public campaign to retain the Renewable Energy Target (RET), which has been subject to a review by businessman Dick Warburton and is set to be either axed or wound back by the government, if the government is able to secure support in the Senate.

Hunt said Grimes had continued to attack the government in public, despite knowing it was committed to renewable energy. Hunt called the solar council chief executive “deceptive” and a “failure” in an unusually strong attack when they both spoke on the same ABC radio show on Thursday.

“We spoke a week ago and I was crystal clear that we remain committed to the renewable energy target,” Hunt said during a testy interview. “He said things which were extraordinary and completely at odds with what he said to me in private. I think John Grimes should be utterly ashamed of himself today. He is someone who says one thing in private, another thing in public.

“[He is] a total failure of an industry leader, someone who is utterly partisan and he should be ashamed of himself.”

Grimes told Guardian Australia that Hunt had made an “unprecedented personal attack” against him.

“He’s so scared by the campaign that he has reverted to playing the man rather than the policy,” he said. “It was absolutely uncalled for and shows how much stress the man is under. The government has got no policy response so it would rather shoot the messenger.

“I’m the wrong target, really. It’s Tony Abbott and his radical anti-renewables agenda that should be his target. That is what is threatening thousands of jobs and 4,500 small businesses.”

The Australian Solar Council held a campaign event in Redcliffe, Queensland on Thursday night, attended by more than 500 local people. Luke Howarth, the local Coalition MP for Petrie, was invited to the event but did not attend.

Hunt, seen as one of the few supporters of the RET in cabinet, is believed to favour paring back the scheme to its current target of 20% of energy generation to be via renewables by 2020. The level of renewables is currently set to overshoot this mark if the scheme is not modified.

The Clean Energy Council, the peak body representing Australia’s clean energy developers, has warned that paring back the RET to a “real” 20% would reduce the amount of new large-scale renewable energy built by 64%.

New large-scale solar and wind projects have reportedly been imperilled by uncertainty over the RET. The Clean Energy Council has warned that more than 18,000 jobs and $14.5bn in investment will be lost if the RET is scrapped.

It is understood that Tony Abbott is in favour of dismantling the RET scheme entirely, while Hunt wants it pared back. Warburton’s review of the RET was delivered to the government last week, but has still not been publicly released.

Hunt said the government, unlike the previous Labor administration, was focused on “long-term stability” in the renewable energy industry.

The Coalition wants to axe both the Australian Renewable Energy Agency and the Clean Energy Finance Corporation – the government’s two main clean energy bodies. The government has also reversed its pledged support for the $500m One Million Solar Roofs program by completely gutting its budget.

Mark Butler, Labor’s environment spokesman, said Hunt’s criticism of Grimes was “unbecoming of an elected representative”. “It’s entirely inappropriate for a minister to take out his anger with his prime minister on a stakeholder and journalist,” Butler said.