NSW Premier Dominic Perrottet has threatened to tear up a wage deal with the state’s train union in a hardline stance on industrial action to end a wave of strikes crippling Sydney’s public transport system.

As NSW commuters endured hour-long waits for trains and stood stranded at stations because of a strike affecting 75 per cent of services, the premier handed the state’s rail union an ultimatum to accept a $1 billion enterprise agreement or have it terminated.