Greens leader Richard Di Natale says his party can win eight extra lower house seats in the next decade and is targeting sitting Liberal MPs as well as traditional Labor territory in inner-city Melbourne and Sydney.

In an interview to mark his one-year anniversary as the party's federal leader, Senator Di Natale has declared the Greens could serve in cabinet in a future coalition with the ALP.

But he delivered a stinging rebuke to Labor critics of his party, arguing they are "angry because many of them know that we are right, and for their own opportunistic, political reasons they have to vote against things that they know in their hearts are right".

"We remind them that they once had a conscience," he said.