The union's Canberra branch secretary, Klaus Pinkas, said there was room for savings in the workers' compensation scheme, as sought by the government, and the union was part of the ACT-wide review of the scheme.

But it was "bullshit" that drivers had a veto over the bus network, as suggested by Municipal Services Minister Shane Rattenbury. The union only had a say over shift changes, not the bus network or timetables, he said.

As for weekend and public holiday work being voluntary, Mr Pinkas said that was part of the drivers' agreement that didn't expire until 2017.

"This is part of the problem. You've got a bunch of people in the government, including the chief minister and including the minister, who haven't even read the agreement don't understand how it works and they make these assumptions and they're just plain wrong on them," he said.

"The bottom line is, yeah, sure you can make things cheaper by reducing the wages of the drivers. Sure you can, but we refuse to believe that's a reasonable outcome. From our point of view, it's not the way to go."

Asked again about his suggestion that drivers had a veto over routes, Mr Rattenbury said on Friday. "It is the case that the union must agree to shift changes and major network changes before they can be implemented."

Despite the agreement having two years to run, the government would work with staff to put in place "a range of efficiencies", he said.

The government has identified workers' compensation as a target area.

Comcare data shows a steady decline in compensation claims from ACTION staff over 10 years, with 75 claims submitted in 2005 (67 of which were accepted), compared with 46 claims submitted in the past 12 months (36 of which were accepted, with four still being considered). Sprains/strains and back injuries account for by far the most claims, with occupational overuse injuries the next most common.

In the past 12 months, there were 15 claims for sprains and strains, nine for back injuries and six for occupational overuse.

Claims have cost more than $6 million a year in recent years (including likely future costs), although that has dipped in the most recent year to $4.2 million (an average of about $120,000 per claim).

Mr Pinkas said it was not surprising that drivers made workers' compensation claims, given the nature of the job – driving 10 or 12 hours a day was inherently bad for you, he said.

He put the Anzac Day confusion down to a government stuff-up, saying Monday, April 27, should have been declared a public holiday, as it had been the last time Anzac Day coincided with a weekend. And far from drivers refusing to work, he said had been no particular push for management to get drivers on the day – they had simply been asked to put their name on a list if they wanted to work.

While a number of drivers had made other arrangements for April 27, there was no shortage of drivers being prepared to work weekends, and they were lining up for the work, he said.

"In case they haven't noticed, the buses are running on the weekends."

Mr Pinkas said despite the government's public calls for reform in recent days, and Chief Minister Andrew Barr's threat to bring in private operators to run the buses if he couldn't push through reform, no one had approach the drivers or union for talks.

"Nobody's said anything to us about making changes," he said "We think this idea of the privatisation stuff is thrown out there as a bit of a red herring to cover for the fact that they stuffed up the Anzac Day thing and they've got a bit of egg on their face over it," he said.

Mr Barr's spokesman said the government had judged it particularly important this year that the holiday fell on Anzac Day itself to give people who might otherwise have to work on a Saturday the chance to observe the day. Additional public holidays also put pressure on businesses, he said.