Greens confirm election preferences

The Greens will put Labor ahead of the Liberals in 139 of 150 lower house seats and all Senate seats up for grabs in the federal election.

However the minor party has supported a move by some of its branches to issue open tickets - where no preferences are recommended - in 11 lower house seats.

"While we think the Labor party can do a lot better on the issues that matter to many Australians, like climate change and treating people seeking our help with decency, they are a better choice than the Liberals and Nationals," the Greens said in a statement on Monday.

Former Greens leader Bob Brown said he believed voters should make up their own minds when it came to preferences.

"I do say to everybody ... vote one Green and then put your preferences where you think they should go in both houses," he told reporters in Adelaide.

Asked whether the Greens should resist telling voters how to vote, Dr Brown said it was a matter for the party leadership to decide.

"I'm very, very happy with what the party's doing ... they're much more smart and alert to how things are going in 2016," he said.