Well-known property owner Sotiria Liangis has been in a long-running legal stoush with the ACT's Conservator of Flora and Fauna over a protected tree in Manuka.

The battle in the ACT Civil and Administrative Tribunal centres on Liangis Investments' bid to have the protected London Plane tree removed from the block housing the Capitol Cinemas the company owns.

But the case late last year also highlighted an "anomaly" in the Tree Protection Act that did not allow for a merits review process of the Conservator's decisions, and the government has introduced a bill to rectify the situation.

The Tribunal found that under the current laws, the only person who could apply to deregister a tree was the individual who nominated it in the first place, who may not live as long a registered tree.

Liangis Investments had also applied to complete a "tree damaging activity" on the tree in July last year, but the reforms proposed could provide the company with a new legal avenue to deregister the tree.

While the legal battle continues, Transport and City Services Minister Meegan Fitzharris on Thursday introduced the changes to enshrine a merits review process in the Act.

Ms Fitzharris said in the assembly the changes would let the Conservator make a decision to deregister a protected tree "without following the full consultation process that would normally apply to the cancellation".

But she said the changes would not stop the Conservator from following the full consultation process, involving notifying the original nominator and neighbouring lessees, where "it is not clear whether the trees death has been natural".

Ms Fitzharris said due to an "anomaly" in the Tree Protection Act, created when all territory acts were updated to create the Tribunal, there was "currently no exercisable right of merits review" in relation to the Conservator's decisions.

Under the proposed changes, those given the right to apply to the Tribunal for reviews of decisions like deregistering protected trees included the original nominator, the lessee of the land on which the tree stands (or the relevant land agency).

It also allows land territory lessees within 50 metres of the tree the right of review, as well as the Heritage Council, if it gave advice on the original nomination, but not to other people or groups without a "direct interest".

Ms Fitzharris said it was appropriate that merits review was only extended to those with a direct interest and that "in this case that direct interest can be identified as a proprietary interest in land potentially impacted".