Labor and the Greens will use their combined numbers in the Assembly today to defeat an attempt by the Liberals to bring a motion of no-confidence against Chief Minister Ms Gallagher over her handling of the health portfolio.

Back in 2000, then Liberal chief minister Kate Carnell resigned after it was clear a majority of Assembly members would support a no-confidence motion over breaches of the Financial Management Act related to the Bruce Stadium redevelopment.

Ms Carnell, who is now the chief executive of Beyondblue, said yesterday she had been brought down due to ''victimless'' errors that a public servant had made without her knowledge or consent.

''Back then Labor and the crossbenches perceived clearly that ministerial responsibility meant that a minister had to be responsible for things that happened within their portfolio responsibility, whether or not they were personally involved or knew about it,'' she told The Canberra Times.

One of the issues raised in the Liberals' no-confidence motion against Ms Gallagher is the Canberra Hospital emergency department data-tampering affair.

Ms Gallagher was cleared of any involvement in the tampering, and former hospital executive Kate Jackson took responsibility for most of the changes made to patient waiting time records.

Ms Carnell said in her own case she had had no knowledge of the Financial Management Act breaches but had still had to take ministerial responsibility for them.

''The view of the Assembly at the time was that there was no indication that I knew about it - in fact I think everyone accepted I didn't - but it was contrary to the Financial Management Act and I was the responsible minister. It's that simple.

''Then the Labor Party and the crossbenches perceived that ministerial responsibility clearly meant that the minister responsible should take the fall.''

Ms Carnell said she had taken ministerial responsibility for what had occurred but argued at the time that it should not be a hanging offence.

She said she would be very interested to know why the Assembly's interpretation of ministerial responsibility was now ''really different''.

Ms Carnell said it was a matter for the current Assembly to decide whether it had confidence in Ms Gallagher to remain Chief Minister.

Ms Gallagher's office last night declined to comment on Ms Carnell's remarks.

ACT Greens Leader Meredith Hunter said she was not in the Assembly in 2000 but was confident Ms Gallagher had no case to answer.

''We're looking at what's presented before us at this time and part of that is an Auditor-General's report which clears the Chief Minister of any wrongdoing,'' Ms Hunter said.

Ms Gallagher yesterday visited the Canberra Hospital to officially launch new cancer treatment equipment as some patients were being moved into the new Centenary Hospital for Women and Children. She said there were still pressures in some areas of the health system but she had helped deliver many improvements as minister. ''I know my record in health will stay true. In six years we've delivered a lot,'' she said.

Police confirmed yesterday they were investigating the data tampering affair, and were currently assessing whether an offence had been committed. The matter was referred to police on July 4 by the ACT Health Directorate.