Canada’s largest federal union has asked Prime Minister Justin Trudeau to call a public inquiry into the Phoenix pay disaster and the culture in the public service that led to the colossal failure.

The Public Service Alliance of Canada has been talking about the need for a public inquiry since its national convention in April, but sent a formal written request to the prime minister this week, said president Chris Aylward.

The call for an inquiry comes as Privy Council Clerk Michael Wernick and Auditor General Michael Ferguson lock in an unprecedented clash over Ferguson’s conclusion that Phoenix was an “incomprehensible failure” that revealed a cultural crisis within the public service.

Aylward said he was “absolutely floored” that Wernick, the head of the public service, rejected Ferguson’s conclusion, hardening the union’s resolve for a public inquiry.

“It’s not just the auditor general he will be battling with, it’s public service workers generally. It gives even more credence for why we need a public inquiry when our top public servant dismisses the report.”

Wernick took issue with Ferguson’s message that preceded his report into the planning and implementation of Phoenix. He called it opinion that was not supported by evidence and said Ferguson unfairly generalized that the mismanagement of a handful of Phoenix executives signalled a widespread cultural problem. He maintains that Phoenix executives took such high risks that the debacle was “comprehensible and avoidable.”

Aylward said Ferguson’s two reports on Phoenix, coupled with a Goss Gilroy report, point to problems that led to the Phoenix debacle that have yet to be addressed, such as accountability, culture and the evidence of rank-and-file employees.

He said employees were never consulted about the planning and implementation of Phoenix and the inquiry will give them a chance to testify about the problems, the culture and the personal impact of botched pay.

Unions strongly protested the rollout of Phoenix and appealed to Public Services and Procurement Canada to stop or delay the second and largest wave of the rollout in April 2016 because Phoenix wasn’t working and the Miramichi, N.B. pay centre was already overwhelmed.

He said the unions’ ignored pleas drives home the belief that management doesn’t listen, which has created a reticence about bringing bad news forward. Ferguson found the Phoenix executives didn’t pass information about the extent of problems up to the deputy minister and that those who knew about problems didn’t step forward either.

Aylward said Phoenix was the “pinnacle” of the chill on telling the truth. He said that many employees are afraid or reluctant to tell the truth and come forward with problems because the prime minister, minister or deputy minister want the job done.

“They say ‘maybe I should just do the work, knowing its going to fail because I am being told to get it done.’ That is the culture,” said Aylward. “We don’t give the commands to get work done. We are the ones trying to raise issues and we are being dismissed or ignored because the edict from above says get it done.”

Aylward said an inquiry would also deal with “individual and structural accountability” for Phoenix. He said the key executives responsible for Phoenix should be called to testify about the decisions they made and why. Public servants are frustrated when there are no consequences for major errors and failures “and that’s a problem.”

Although Wernick doesn’t think the culture is broken, he acknowledges the public service has problems and is pressing for a major structural overhaul. It needs delayering; fewer levels of executives; better ways to get rid of poor performers; new incentives and massive overhaul of the human resources regime.

There are currently 80,000 pay rules and allowances and 670 occupational groups that Wernick said must be reduced and streamlined or any new pay system will run into similar problems as Phoenix.

Aylward said he is prepared to work with the government to streamline rules and processes as long as unions don’t have to make concessions. He said many of the pay allowances, for example, could be rolled into salary but eliminating them would be a concession unions wouldn’t accept.