While Ipsos public affairs director Jess Elgood noted an 8.3 per cent margin for error given the relatively small number of young voters surveyed, she said the April Fairfax-Ipsos poll result demonstrated the competition Labor would face from its left flank at the July 2 election. The figure also raises questions about the political wisdom of Labor's proposal to reduce the voting age to 16. The younger people are, the more partial they are to the Greens. Bringing in roughly 500,000 16 and 17-year-olds could be a major boost for their left-wing rivals. Labor senator Sam Dastyari, the party's 32-year-old shadow parliamentary secretary for youth, said the strength of the progressive vote deserved attention from his party. "This all presents a challenge and an opportunity for the Labor Party. It's a challenge because it demonstrates that there is a youth vote that requires a certain focus but it's an opportunity because when we actually present our case and talk about the issues, we can win their votes," Senator Dastyari said.

He said the Greens had actively targeted young people and promised Labor would increasingly do the same. The good news for Labor - and the Coalition - is that there is a consistently strong relationship between ageing and conservatism and many young voters move to the centre with time. But the erosion on their left flank will remain a challenge. The rise of the Greens - and their increased focus on left-wing issues beyond the environment - has coincided with Labor's perceived move to the centre. On Thursday afternoon, Deputy Opposition Leader Tanya Plibersek and former treasurer Wayne Swan shared photos on social media of themselves when they were younger. They urged people to enrol to vote and highlighted penalty rates, affordable housing and same-sex marriage as issues at stake. Senator Sarah Hanson-Young, the Greens' spokeswoman for youth, said the party's appeal to young voters was based on policy.

This all presents a challenge and an opportunity for the Labor Party "You can see how, over time, issues that once only the Greens and young people supported have become mainstream. We saw it with marriage equality, concerns around global warming and the need for a fairer way to treat people seeking asylum," she said. "These are all issues that speak to the future of our nation."

Ms Elgood said while the younger demographic tended to be fickle, they were consistently issues driven, more ideological and less aligned to one party. "That's important for the Greens vote," she said. "Having done focus groups, climate change, refugees and same-sex marriage are issues that draw a greater response from young people than taxation, pensions, mortgages and other issues that older people think about more." As of August 2015, 88 per cent of 18-24 year olds support same-sex marriage, compared to 68 per cent overall.