Both leaders faced questions on their costings, with hundreds of millions of dollars' worth of policies from both sides yet to be scrutinised by Treasury.

Liberal leader Alistair Coe failed to submit some of the party's most costly and significant promises to Treasury for costing.

Those promises included their pledge to halve elective surgery waiting times, add eight theatres to the Canberra Hospital expansion without added costs, and freeze residential rates for four years. However, Mr Coe said the Liberals had been honest and accountable.

"Every single day I've been before the media, I've been knocking on doors, I've been at shopping centres, I've been around Canberra talking about our polices," he said.

Labor has submitted its major polices for costing, however some of those policies were only received by Treasury on Wednesday. It means Treasury may not have time to complete those costings.

Mr Coe was asked why he had repeatedly refused to directly answer questions in his daily media conferences.

He did not answer the question, but said Labor was "old and tired" and arrogant. The Liberals used the second-last day of pre-polling to erect a wall of boxes with the slogan "cost of living" on it, before knocking it down.

Meanwhile Labor headed to the EPIC testing centre for its daily media event. Mr Barr used the event to mark 100,000 COVID tests taken in the ACT.

He was asked if Labor was relying on its response to the pandemic to be re-elected.

"I wouldn't say relying on it, but we certainly put it forward to the community as evidence of what an experienced, progressive government can deliver for this city," he said.

"I do take issue with what [Coe] has done at various points in the pandemic ... I think that's appropriate because it does go to questions of leadership, of judgment, and how you manage a crisis like this - and they are issues that are front and centre in this campaign."

The ACT Greens said they would push to expand the midwife-led birth centre at Centenary Hospital for Women and Children, as well as explore a stand-alone birth centre.

The party said while the birth centre had high levels of satisfaction and good clinical outcomes, many mothers missed out due to long waitlists.

"The Greens know that birthing centres are a great option for so many parents, and we want these options expanded so more parents can access it," the party's Murrumbidgee candidate Emma Davidson said.