Dozens of protesters gathered outside a Perth hotel on Friday as the ASX-listed company held its annual general meeting.

Vimy is pressing ahead with its proposed development of Mulga Rock, Australia's third-largest undeveloped uranium site.

The site, located 290km northeast of Kalgoorlie, is known to contain 76.8 million pounds of uranium in four deposits, which Vimy intends extracting using shallow open-pit methods.

Environmental groups have urged the state and federal governments to urgently investigate a potential breach of conditions at the primary mine site, on the southwestern edge of the Great Victoria Desert.

They have cast doubt on the viability of the $393 million project given state environmental approval expires next month.

A final investment decision is not due until next year.

However on Friday, Vimy said it had formally notified regulators of "substantial commencement" of the Mulga Rock project as required under the approval process.

Interim chief executive Steven Michael said the company had cleared land intended for the open cut mine pit and an accommodation village.

"The foundations are now in place to build a long-life, strategic resource project for Western Australia, and the board of Vimy is focused on rapidly advancing Mulga Rock to its next development milestone," he said in an ASX announcement.

"Vimy will continue to work cooperatively with the various state and federal government departments to obtain the approvals required to ensure Mulga Rock delivers first uranium production in 2025."

The Conservation Council of WA and Australian Conservation Foundation say works at the site are "pointlessly destructive", claiming Vimy lacks a series of required approvals and does not have the capital to start mining.

They insist rapid clearing of vegetation for an airstrip there is happening without a necessary conservation plan and in an area beyond that covered by national environment law.

It's also said to be unacceptably close to where the rare sandhill dunnart marsupial has so far managed to survive despite the encroachment of livestock and predation by introduced foxes and cats.

The McGowan Labor government has banned uranium mining but it does not apply to projects which had already been approved.

WA's Environmental Protection Authority has said it is assessing claims Vimy is moving ahead with a proposal which is now materially different to what it originally submitted in 2016.

A spokesman for federal Environment Minister Sussan Ley this month told AAP her department was aware of certain claims and "making a number of inquiries".

Australian Associated Press