Anthony Albanese was unveiling a $1 billion package, which included a boost in the number of Medicare mental health centres and additional services for young people, when a protester burst into the press conference on Tuesday.
"You say you care about young people and yet since getting elected your government has approved new coal and gas mines," the young woman yelled.
"You're condemning young people like me to a life of climate disaster."
It was the second time the prime minister has been heckled on climate and the third time an outsider has gatecrashed his campaign events, though activists from Rising Tide have also interrupted the opposition leader on the election trail.
The latest heckler was quickly pushed outside, but her message echoed youth mental health concerns raised earlier.
Developments over recent decades like rising student debt, the surging cost of housing and climate change made the lives and futures of young people "much more challenging and pessimistic", University of Melbourne psychiatrist Pat McGorry said as he welcomed Labor's promise.
"Young people are the miners' canaries of society, they're showing up with symptoms of a society that's heading in the wrong direction," he said.
"We need to identify what those problems are and then turn the direction around."
Labor's package allocates $225 million for new or upgraded Medicare mental health centres - "entry point" facilities which allow patients to access free consultations with professionals but are not designed to offer longer-term ongoing care.
An extra $200 million will be spent on 58 services run by mental-health organisation Headspace, either to set up new locations or expand existing ones.
The announcement also includes $500 million to set up 20 youth specialist care centres, designed to deal with young people who have mental health conditions such as eating disorders or personality disorders.
"I want every Australian, particularly every young person, to be able to access the mental health care that they need," Mr Albanese said.
A further $90 million would be spent on helping to train 1200 mental health professionals.
The Royal Australia and New Zealand College of Psychiatrists urged the coalition to match Labor's workforce investment.
Opposition Leader Peter Dutton said Labor was playing catch-up on coalition policies.
It has pledged to double the number of Medicare-subsidised psychology sessions should it form government at the May 3 poll.
Patients were offered 20 subsidised sessions during the peak of the COVID-19 pandemic as a temporary measure under the former coalition government and Mr Dutton has called for the sessions to be restored.
"(Clinicians) need more services to deal with complex matters, and that provides them with more income, more revenue and more incentive to practice in this area," he told ABC news.