A lawyer representing activists against the Western Highway duplication said he is hopeful another legal push can continue to halt to works on the project.
Michael Kennedy has been working on potential challenges to Federal Environment Minister Sussan Ley's decision not to make declarations protecting six trees that would be impacted by the duplication.
Mr Kennedy represents the group of Djab Wurrung traditional owners who are against the duplication.
He said he is in the process of putting together paperwork to challenge Ms Ley's decision.
"Over the last several days I have been busy with several things. One of which is trying to secure a meeting between Vicroads, Major Roads and traditional owners to consider an alternative alignment for the highway," he said.
"I have also been going through the minister's reasons for her decisions to show how we believe she had failed to account for relevant matters.
"We are of the belief those matters are grounds for us to apply for a judicial review."
The challenge of Ms Ley's decision presents one of the final opportunities to challenge the highway duplication, with Major Roads Projects Victoria now able to commence works as soon as possible.
"My decision allows the planned upgrade to proceed, subject to any separate planning and regulatory requirements," Ms Ley said.
"My decision fully addresses the application made under the Aboriginal and Torres Strait Islander Heritage Protection Act and I do not intend to take any further action in this matter."
One of Mr Kennedy's many arguments he said he will present is around how the 'Northern Route' option was dismissed and "portrayed as more expensive by Major Roads".
Mr Kennedy said he believes he will file an application "in the next week or so" to delay works from going ahead once again.
"They can start whenever they want so for us we need to try and get an appeal to the federal court as soon as we can," he said.
"We would ask the court to say hold on and let's wait just a little longer while we continue to work on alternative arrangements.
"We think the minister has failed in her obligation to protect that region and that is why we will challenge her decision."