The Greens have pledged to push for a strong renewable energy-led economy at the party's campaign launch in Melbourne.

Greens leader Richard Di Natale told the party faithful gathered in North Melbourne that his team offered a real alternative to Labor and the Liberal Party.

"The two old parties are so far gone in their race to the bottom," he said.

"They both support Australia's inhumane treatment of people seeking asylum, they both support new polluting coal mines and neither is prepared to end unfair tax breaks to raise the revenue we need to fund quality schools, hospitals and services.

"We go into this election with our biggest ever federal party room, our biggest-ever membership base, and the most volunteers we've ever had out having one-on-one conversations with voters about the issues that matter to them.

"We are proud to be running candidates in every seat across the country because those seats don't belong to the Labor or Liberal parties, they belong to the community, and the community deserves a choice outside of the Coles and Woolies of Australian politics."

Greens say they could win Melbourne Ports

Melbourne MP Adam Bandt is the Greens' only member in the House of Representatives but the party is targeting four other Melbourne seats at the election — Batman, Higgins, Wills and Melbourne Ports.

The party said new polling shows they are in a position to win Melbourne Ports, which has been held by Labor since 1906.

A survey by Lonergan research asked 1,357 people who they would vote for in the House of Representatives.

Greens candidates Alex Bhathal, Samantha Ratnam, Steph Hodgins-May and Jason Ball (left to right). ( ABC News: Cheryl Hall )

Twenty-seven per cent said they would vote for Greens candidate Steph Hodgins-May, compared to 25 per cent who would vote for Labor's Michael Danby, who currently holds the seat.

Forty-two per cent said they would support Liberal candidate Owen Guest, meaning The Greens could win on Labor preferences.

Greens candidate for Melbourne Ports Steph Hodgins-May said Mr Danby had defied Labor's national executive by handing out how-to-vote cards preferencing the Liberal Party ahead of the Greens.

"There has been a surge of support for the Greens in Melbourne Ports and this poll shows that we're in a position to win this Saturday," she said.

"If Labor fails to rein in Michael Danby then they run the real risk of handing the seat to the Liberal Party, which could be pivotal in who forms government in a tight election."