Engineers and maintenance workers of Qantas based in Sydney are set to walk out of their jobs starting at 3pm as part of a growing labor disagreement with management.

This has resulted in the cancellation of 3 international and 25 domestic flights that should have departed from Sydney airport.

At least 46, 000 passengers will be affected by the work stoppage.

Officials of the Transport Workers Union (TWU) have already denounced the lockout imposed by Qantas management on some 4,000 baggage handlers, freight personnel and caterers working for Australia's biggest airline.

This strike is the latest of mass protest actions conducted by union workers despite an earlier announcement by the TWU that it was abandoning its "planned international action," the Sydney Morning Herald reported.

A total of 17 flights were cancelled and 29 deferred on Friday.

Negotiations between the airline and TWU in the Gillard Labor government's Fair Work Australia (FWA) tribunal last week failed to settle a long-drawn-out clash over a new enterprise accord.

The TWU is asking for a 5 percent annual pay rises for three years and job security clauses to prevent outsourcing and limit the use of contract labor, according to the International Committee of the Fourth International (ICFI).

TWU officials were expected to stop additional strike action and gave up a 48-hour ban on higher duties.

Qantas CEO revealed to the Herald that he received threats to his life but this allegation was called by the TWU as a mere PR gimmick.

The air company has increased its publicity campaign by coming up with massive newspaper advertisements apologizing to passengers and pointing its finger at the union for all the troubles and interruptions.

Meanwhile, the Community and Public Sector Union has refused the offer made by the federal government for a 9 percent increase within the next 3 years.

The engineers are asking for a 15 percent increase in the next 3 years.

More protest actions are expected within the week.