Labor’s candidate for the Melbourne seat of Higgins, Michelle Ananda-Rajah, says the government’s lack of action on climate change will be a decisive issue for voters at the next election, as she eyes winning the seat off the Coalition for the first time in more than 70 years.

Ananda-Rajah, who will take on the sitting Liberal MP, Katie Allen, says climate change is the “number one” issue raised with her by voters, and will be a key part of Labor’s campaign as it targets progressive voters in the affluent inner-city seat.

Like Allen, Ananda-Rajah is also a doctor, and she says the government’s pandemic response – and the pandemic recovery – will be front and centre as voters go to the polls, with an election expected early in the new year.

While Higgins has been won by the Liberal party since it was created in 1949, and was held by the former treasurer Peter Costello for 19 years, it is now held by Allen on a slender 3.9% margin.

Describing the next election as a “watershed election” for the country, Ananda-Rajah said voters would cast judgment on the two key issues of climate change and the pandemic recovery when they went to the polls.

“The problem with this pandemic is that it does suck the oxygen out of all the other issues that are incredibly important that need to be addressed, and haven’t been addressed, and one of them is that other major existential threat that we all are aware of, which is climate change,” Ananda-Rajah told Guardian Australia.

“I want to see Australia reap the health and economic benefits that come from transitioning this country to a climate friendlier future, and I want to see how this is going to be articulated by this government, and after eight years I’ve completely lost confidence in them.

“I think the two big things for my own mind will be, one, looking at developing resilient systems for the years ahead in the aftermath of pandemic, and two, it’s going to be about supercharging our economic recovery and that is going to be intimately tied to transitioning us to a climate friendlier future.”

While acknowledging that Allen – a moderate voice in the government – had been a vocal advocate for a net zero by 2050 carbon emissions policy, Ananda-Rajah said she believed the voters of Higgins would “see through this” and judge the government on its record.

“There is a real disconnect between announcements and action in the Liberal-National party and in the Morrison government, and I think they’ve already seen through it,” she said.

“Katie Allen is kind of furiously trying to paint herself as someone who is pro-climate. Now, that may be the case. The issue, though, is that she’s completely ineffectual in this party, right. She and the other voices that want real change are completely ineffectual, they are impotent.”

Allen rejected the criticism, saying she had been advocating for action on climate change since she was first elected.

“I’ve been a powerful advocate for Australia’s commitment to a net zero carbon 2050 target, which I believe will be delivered in time for Glasgow,” Allen told Guardian Australia.

“I’ve put the national interest first, unlike the Labor candidate who has been fear-mongering about the Covid vaccine for political point-scoring.”

Ananda-Rajah’s position on AstraZeneca has so far been the focus of the Coalition’s criticism, with the Liberal party taking out attack ads against her on social media, targeting her as the “outspoken AstraZeneca critic” and suggesting she has been undermining the national vaccine rollout.

On the ABC’s Q+A program in February, Ananda-Rajah claimed AstraZeneca had “failed in terms of its efficacy”, pointing to early trials, including in South Africa, that showed it was less effective against certain variants.

She said rolling out the AZ vaccine which had been developed against the original strain and then opening the borders would be “a population-level experiment, which has high stakes attached to it, personally I’m not comfortable with that approach at all”.

Ananda-Rajah, a respected infectious disease expert, said her comments on the AstraZeneca vaccine had been in line with the health advice at the time, and maintained that the government’s handling of the vaccination rollout had been “absolutely unforgivable”.

She also cast doubt on the government’s pandemic exit strategy, saying she was concerned people were being given false hope that life would return to normal next year.

“I think there’s a misconception that people have, partly driven by the federal government, that, you know, we are all going to be vaccinated and everything’s going to be fine,” she said,

“Now, that is clearly not playing out in other countries that have much higher vaccination rates than us, so this still has got some years to run. And I would argue that actually it’s not going to be over until the rest of the world is vaccinated and that has been projected to occur sometime in 2024, 2025.

“And one of the reasons I am running is I think that there’s a real vacuum of leadership in this government, what I’ve seen has honestly shocked and appalled me, because instead of actually alleviating the uncertainties of this pandemic, the government has amplified them.

“And they’ve done that basically through a lack of foresight, and a lack of scientific competency in the government, and ineptitude. We need to move from a reactive, panicked government, to a government that is precautionary, and able to actually lead us in a mature way through the challenges ahead, both short, medium and long term.”