"A free fares protest is a great way for bus drivers to continue the strike in a non-disruptive fashion while engaging with their passengers and communities," says Jared Abbott, First Union secretary for Transport, Logistics and Manufacturing.

"Passengers want to know why they're getting free fares and bus drivers are more than happy to tell them - they are hugely disappointed with Go Bus's combative response to run-of-the-mill fair wage negotiations."

However Go Bus says bus rides will not be free on its services in south and east Auckland, and says it's "deeply concerned" the latest strike action by First Union will compromise driver safety.

"By encouraging the small number of union members it has in Auckland to stop collecting fares, First Union is placing the safety of the majority of bus drivers who are working normally at potential risk," says Go Bus HR director Kura Poulava.

"We know from experience these drivers are at risk of intimidation and even assault from members of the public who believe their rides will be free. Promoting such a situation as this is completely irresponsible and needs to stop before someone is hurt."

It comes after claims Go Bus managers attempted to drive over workers during a tense Auckland strike two weeks ago.

First Union says three bus drivers have lodged police reports that they were physically harmed during the incident.

"There is an easy fix - join us in good faith negotiations, listen to the workers, and look at your competitors in the bus industry who pay their workers significantly more," Abbott says.

However Go Bus says it's "very disappointed" at the union for trying to portray the union as being unwilling to negotiate.

"Go Bus has been ready, willing and able to reach a settlement with its drivers who are represented by First Union for some time now," Poulava says.

It is extremely frustrating that the union seems to have abandoned the idea of reaching a deal for its members, and instead has embarked on a pointless and unproductive cycle of strike action.

"The facts speak for themselves: Go Bus has an offer on the table, we have a date for mediation set, yet the union continues to call strikes. This action is the second this week."