The Islands (Scotland) Bill was put forward following the Our Islands Our Future campaign carried out ahead of the Scottish independence referendum to demand more power for the islands.
Orkney Islands Council wants the bill to be strengthened to allow greater devolution of power to the islands.
They also want retrospective island proofing of laws and policy. MSPs from opposition parties have proposed changes to allow these changes to take place.
The Islands Bill faces its final vote at the Scottish Parliament tomorrow.
Council leader James Stockan said: “We believe the Bill could be much more ambitious than it was at stage two of this process.
“We want it to be genuinely empowering, so that it has a lasting and positive impact on the lives of people in Scotland’s island communities.
“The Scottish Government has the opportunity to take forward ground-breaking legislation that would be transformational for island communities like ours.”
Orkney MSP Liam McArthur claimed he had secured support for a key change to the legislation on the eve of the stage three debate.
He said he believed the Scottish Government would now back changes he would put forward to make sure law and policy were not just island-proofed in the future, but this is also applied retrospectively, where requests from local authorities are approved by ministers.
Mr McArthur said: “From the outset, I have made clear that ‘island-proofing’ needs to be able to look back as well as forward.
“Too often in the past, a one-size-fits-all approach to making policy and laws has ignored the needs of island communities, like Orkney.”
Mr McArthur added: “So I am pleased that the Scottish Government now appears willing to accept the case for island-proofing to be applied retrospectively and will be backing my amendment at stage three tomorrow.”
Shetland MSP Tavish Scott wants changes made to make sure Shetland is accurately represented on any public authority maps instead of being boxed-off in a non-geographically correct location.
Islands Minister Humza Yousaf said: “Should the Bill be passed then it will introduce a new duty on Scottish Ministers and the wider public sector to have regard to island communities when exercising their functions and preparing policy, strategies, services and legislation.
“This is known as ‘island-proofing’. This will ensure that there is a sustained focus across the Government and public sector to meet the needs of our island communities”.
Mr Yousaf said the Bill also required the creation of a National Islands Plan. He said: “As Islands Minister I’ve been very privileged to have had the opportunity to help guide the Bill through Scotland’s Parliament.
“I’m very confident it will make a real and lasting impact to our island communities.”