Qantas boss Alan Joyce says he did not discuss the possibility of locking out the airline’s workforce with either the federal government or the opposition before he announced the drastic action last weekend.

Mr Joyce was grilled by senators for three hours on Friday during a fiery parliamentary hearing which ran twice as long as scheduled.

The Senate’s transport committee is examining legislation that would force Qantas to keep its principal operational centre in Australia and offer overseas-based staff the same pay and conditions as local employees.

But senators were more interested in asking Mr Joyce about Saturday’s grounding of the entire Qantas fleet ahead of a proposed worker lockout.

The Qantas chief executive insisted the decision had been his alone – and had been kept secret until the very last minute.

“That was my decision absolutely,” he told the hearing in Canberra, adding it had later been endorsed by the Qantas board.

“I have complete operational discretion.”

Mr Joyce said he had spoken to federal ministers, shadow ministers and state politicians in the weeks before Saturday’s action to explain that the entire fleet could be grounded “at short notice”.

“At no stage did I talk to anybody about lockouts.”

Transport Minister Anthony Albanese this week suggested the opposition may have colluded with Qantas in an “orchestrated campaign” prior to Saturday’s announcement.

At one point Friday’s hearing became so heated that Labor backbencher Doug Cameron – who wasn’t getting the answers he wanted – compared Mr Joyce with former US president Richard Nixon who was nicknamed “Tricky Dicky”.

The Qantas boss returned fire with, “You’re a bit like a McCarthy trial.”

Greens leader Bob Brown accused Mr Joyce of being “obscure and devious” about the decision to lock out employees.

“You set out in at least the week before grounding the fleet to deceive the government and this parliament by withholding your plan for a lockout,” he said.

“The reason … is because you didn’t want the government to intervene and prevent the lockout.”

After Qantas told the federal government of its plan at 2pm (AEDT) on Saturday the government asked the industrial umpire to intervene.

Fair Work Australia eventually terminated all action in the early hours of Monday and flights resumed that afternoon.

Mr Joyce told the hearing it had been “a mistake” to continue taking bookings until 8.30pm (AEDT) on Saturday when the fleet had been grounded more than three hours earlier at 5pm (AEDT).

Qantas would compensate customers “above and beyond” what had been recommended by the Australian Competition and Consumer Commission, he said.

“That was always our intention and you’ll see on Monday what we’re doing.”

Mr Joyce said it was a conspiracy theory to suggest Qantas had started preparing for the grounding before Saturday.

He noted that Jetstar boss Bruce Buchanan couldn’t be tracked down initially for Saturday’s board meeting and three members of his PR team were stuck in Melbourne at the races.

They had to fly back to Sydney on Virgin.

Mr Joyce said if there was a conspiracy Qantas conducted it “woefully”, to which Senator Cameron interjected: “That could be called an alibi.”

Senator Cameron insisted the airline could have gone to Fair Work Australia and warned it was going to lock out its workers if all industrial action wasn’t terminated.

But Mr Joyce said that wasn’t an option because unions were “slow-baking” the company and it would have taken a year to meet the required threshold for intervention.

“The only alternative to me was to bring it to a head.”

The proposed changes to the Qantas Sale Act would threaten the airline’s viability, he said.

They would force the flying kangaroo to sell off Jetstar and abandon its planned expansion into Asia, and that would result in job losses.

“If we don’t adapt and change Qantas won’t be around,” Mr Joyce said.

The Transport Workers Union (TWU) presented to the inquiry, while it was in camera, an email received by a company which contracted employees to Qantas, warning of the grounding a week before.

TWU federal secretary Tony Sheldon said outside the hearing the email indicated the grounding had been planned.