That's according to three specialists able to perform the procedure, in a letter written to former Health Minister Meegan Fitzharris last year and obtained by The Canberra Times.

The doctors were advocating for better access to endovascular clot retrieval - a potentially life saving procedure for certain stroke patients - which is currently only available in Canberra during business hours.

Canberra Health Services CEO Bernadette McDonald said a 24 hour service would be running at Canberra Hospital by the end of the year, and that significant progress had been made since the letter was written.

The consultant doctors wrote to Ms Fitzharris in October last year - in a letter released through freedom of information laws - saying the then state of play was "unacceptable and unethical".

"We are a committed group of consultant clinicians involved in the delivery of hyperacute stroke care and are contacting you due to our increasingly grave concerns regarding the state of delivery of stroke services in the ACT," the letter read.

The doctors were two Canberra Hospital specialists - Dr Shivendra Lalloo and Dr Peter Mews - and Calvary Public Hospital stroke service director Dr Yash Gawarikar.

They said the ACT had the expertise to deliver a formal 24 hour service but it was still being performed on an ad hoc basis.

"The process of establishing a full fledged [endovascular clot retrieval] service has been bogged down in a number of committees and round table discussions, which appear to be going nowhere," the doctors said.

"In our opinion, this current state of play is completely unacceptable and unethical.

"If urgent action is not taken to address this situation then the organisation will be liable to face legal action from patients not receiving the accepted standard of care."

The doctors said an analysis of data showed 80 per cent of north side patients who were eligible for the procedure between September 2016 and September 2018 did not receive it.

The doctors pointed to a situation in Adelaide in 2017 where patients didn't receive the procedure and were left with lifelong disabilities.

"They chose to sue the hospital and the ensuing coronial investigation found that the Royal Adelaide Hospital was in breach of its duty of care by not providing [endovascular clot retrieval] services," they said.

"We believe that the Canberra Hospital and ACT Health are potentially in a similar precarious situation."

The doctors said they were approaching the minister directly as they had failed to achieve any substantial progress in three years.

"We take a view that the current administrative channels have proven to be ineffective and progress impeded by inertia, indecision and political infighting," they said.

An endovascular clot retrieval procedure involves removing blood clots in the brain with a retrievable stent in cases of acute ischemic stroke.

Ms McDonald said she had worked closely with the three specialists since joining the organisation in October to ensure the service would be up and running by the end of the year.

"I am pleased that Canberra Hospital will become the 12th hospital in Australia to offer a 24-hour clot retrieval service for stroke patients," she said.

"Developing the expanded 24-hour service has required careful planning and full clinical staff engagement across the organisation to ensure the service is always delivered in the safest way possible to provide the best outcomes for stroke patients.

"Canberra Health Services is very fortunate to have on its staff a highly skilled and committed team of clinicians with expertise in this life-saving procedure. I'd like to thank those clinicians for working cooperatively to expand the service."

A Canberra Health Services spokeswoman said work was underway with relevant stakeholders to ensure that the required clinical and support staff, facilities and equipment were available 24 hours a day.

The procedure began being offered during business hours in 2015 with 99 performed at Canberra Hospital since that time.

There are now pathways in place to transfer patients to Sydney who require the procedure out of hours, but it is a time critical treatment.

So far eight patients have been transferred interstate.

"If deemed suitable for clot retrieval and there is no local interventionist available after hours, clinicians call the Royal Prince Alfred Hospital, which can accept the patient," the spokeswoman said.

"An urgent transfer to Royal Prince Alfred Hospital is facilitated.

"Once patients are stable post-procedure, they are transported back to the receiving hospital."