Co-convener Mr Harvie told the party’s autumn conference in Perth that there was an “unresolved democratic deficit” between the 2014 vote for Scotland to remain in the UK and this year’s referendum on EU membership, in which 62% of Scots voted to stay in the EU.
He also made a direct appeal to Labour No voters to join the independence movement as a means of delivering nuclear disarmament and an end to Tory austerity.
Mr Harvie was addressing delegates at Perth Concert Hall the day after the Scottish Government launched a consultation on a new draft Referendum Bill, aimed at giving voters north of the border the chance to consider the issue afresh after the Brexit vote.
The Glasgow MSP said: “Scotland’s mandate, that 62% remain vote, is being utterly ignored by Theresa May’s Government. Well, we will respect that mandate. We will commit to keeping Scotland’s place in Europe because that’s what the people living here voted for.
“And yes, one of the consequences of this vote is that the Scottish Government must be supported in the decision to publish a consultation on a Bill for an independence referendum, because there is an unresolved democratic deficit, a fundamental conflict.
“Much as we voted and campaigned for a Yes vote, and others did, Scotland voted two years ago by 55% to remain part of the UK. Scotland voted this year by 62% to remain part of the European Union.
“Even if the Better Together campaign had not tried to pull the wool over people’s eyes by saying that voting Yes to independence... would be a threat to our membership of the European Union, and even if the Leave campaign had not been riddled with lies, there is a fundamental conflict still between those two referendum results and it may yet come to pass that the only way to resolve them is to put it to the people once again.”
Mr Harvie added: “I think we have the opportunity and the responsibility to reach out to some of those, to many of those, who may not have been convinced in 2014.
“People who perhaps thought long and hard about that referendum and ended up voting No, many of them Labour voters who share much of what we would like to see in a fairer, more sustainable, more just society and who increasingly see that Labour is not in a position to deliver it.
“We can deliver that, so I say to those people who weren’t convinced in 2014, help us deliver it, join our cause.”
The Scottish Greens will hold a debate at their conference on the decision taken by the party to begin laying the groundwork for a Green Yes campaign.
Mr Harvie argued that a currency union between an independent Scotland in the EU and a UK outside would “prove even more unconvincing than it did in 2014”, and said his party would “build the case for Scotland to overcome its remaining over-reliance on the fossil fuel industry”.
He added: “We cannot afford and we will not permit a new Scottish economy and a new Scottish currency to be a petro-economy or a petro-currency.”