Sydney train strikes: Dominic Perrottet bets the house on a public relations war

Senior MPs including the treasurer, Matt Kean, have sought to draw attention to the links that the head of the Rail, Tram and Bus Union, Alex Claassens, has to the Labor party and his position on its powerful administrative committee.

Perrottet said on Wednesday that after 58 meetings with the RTBU and affiliated unions, he was finished negotiating.

If they vote it down, Perrottet said, the government will seek to terminate their enterprise agreement in the Fair Work Commission.

That decision blows out the timeline of this saga for months. It will probably take between five and six weeks just for any ballot to be completed.

Such a timeline would take us into the new year, when both sides will be well into campaign mode ahead of the March election.

The government knows this. In making the decision to escalate the dispute, Perrottet and his industrial relations minister, Damien Tudehope, determined they had no other choice.

For the unions, the question is whether they want to risk a fight in the commission.

There are also risks for the government. For one, the strategy assumes people care enough about the vagaries of an industrial dispute to pick a side.

There are also broader issues at play. The ability for employers to petition to terminate enterprise agreements has been a bugbear for unions for some time, and it was only this month that the federal industrial relations minister, Tony Burke, was critical of employers who made threats to cancel agreements.