A statement from the Communications, Electrical and Plumbing Union accused the big telco of trying to "cripple workers’ right to take symbolic protected industrial action, and its refusal to provide workers with a fair pay and conditions".

The CEPU said it had planned to undertake minor forms of industrial action but claimed Telstra had escalated the dispute by threatening to cut the workers' pay if they indulged in action, even if it was outside working hours.

CEPU Communications Division national president Shane Murphy said: “This week we notified Telstra that we planned to take a minor form of protected industrial action. The planned action would have seen workers refuse to log-on to Telstra’s job allocation system 30 minutes prior to their paid start time. This was designed to be a symbolic action to represent workers’ discontent with Telstra’s pay offer, while having minimal impact on customers.

"Disgracefully, Telstra responded to this by notifying workers that they would be punished with the removal of a whole day’s pay for each and every day they engaged in this minor action within non-paid hours.

“Telstra’s threat to dock workers a whole day's pay for this minor action, during unpaid time, meant that workers would be locked out of their employment and customers would be significantly impacted.

“Telstra’s response shows the contempt the executive group has for its workforce, and for its customers."

Murphy said protected industrial action was being taken because Telstra was allegedly trying to force workers to take a pay cut, in real terms.

"Workers have spent many months trying to get Telstra to come to the table with a fair wage offer, and all Telstra is doing is axing jobs and slashing wages," he said.

The strike will mainly affect maintenance, including diagnostics, testing, new service provisioning including NBN connections, fault repairs and investigations.

“Of course, we never wanted to be forced to take protected industrial action, but Telstra hasn’t left us with any other option," said Murphy.

“Thousands of Telstra workers across the country will send a message on Tuesday that it’s time to take the workforce seriously. We can’t continue to let those at the top of Telstra attack its workers and drive our once-iconic telco into the ground.”