For the next two Mondays, commuters will be able to ride trains for free as part of ongoing industrial action led by the Rail, Tram and Bus Union (RTBU) and its members.

As part of the union’s attempts to secure a new enterprise agreement, station staff will keep ticket barriers open on August 12 and 19, when authorised officers will refuse to check Myki tickets and booking-office staff will refuse to sell or upload Myki cards.

Additionally, from August 12 to 18, train drivers will refuse to alter services outside of timetable schedules. This move is to avoid the practices of station skipping, diverting trains around the City Loop, and short shunting (when passengers are forced to disembark before reaching their destination). Metro Trains can face penalties of up to $1.25 million each month if it fails to run 92 per cent of trains on time.

During this period, train drivers will also refuse to operate trains that don’t have functioning passenger emergency intercoms, nor will they update management on non-safety-related critical information.

The RTBU also announced an indefinite ban on wearing uniforms for any commuter-facing employees beginning August 12.

“This industrial action is aimed at Metro’s hip pocket, not the travelling public,” said RTBU Victorian branch secretary Luba Grigorovitch in a statement. “The RTBU is seeking to keep the public well-informed of any impacts ahead of any industrial action, however these action items announced today are designed to target Metro and will not impact commuters’ ability to catch the train.”

"This is a very disappointing outcome – industrial action is a completely unnecessary step. This action is still avoidable, and we encourage the union to reconsider," says a Metro spokesperson in a statement. "We will do everything in our power to minimise disruptions to our passengers as a result of any action taken."

The industrial action was endorsed by RTBU members in a ballot on July 29.

So get ready for two free days of travel in giant Nacho Cheese Shapes boxes.

This article was updated on August 5, 2019 at 5.41pm.