This is why the party has trouble dealing with a union or its leader who, like John Setka of the CFMMEU, have been destructive or politically embarrassing.

It's both a public issue and a family feud.

However Labor has had some practice, though usually it has been from government rather than opposition.

Perhaps the most dramatic was in the winter of 1949 when Ben Chifley's government used troops - among a suite of draconian measures - to break a coal miners' strike in NSW.

About 2500 soldiers worked 10 open cut mines until the strike, almost certainly communist-directed, was broken.

It was the first time Australian military forces had been used against strikers in peacetime and set a precedent that governments of both persuasions were occasionally to use.

The Hawke government used it in 1989 when the pilots' strike - in support of a big pay rise - disrupted domestic travel and damaged tourism.

The government used RAAF planes and pilots to provide some services until the strike was broken.

In this case, however, the strike was run by the Australian Federation of Air Pilots - hardly a typical trade union and not affiliated to the ALP or the ACTU. This made it easier for Hawke to savage it.

Three years earlier Hawke's government deregistered the Builders Labourers Federation, while its national secretary Norm Gallagher was jailed (though freed on appeal) for corruptly obtaining building materials for his holiday house.

The main public reason for deregistering the BLF was corruption, much of it uncovered by a royal commission.

But the government was also angered by the BLF continuing to demand big pay rises, which threatened the accord with the ACTU under which demands were moderated in return for social benefits.

The cut-adrift BLF members ended up becoming the "C" (for construction) division of the CFMMEU.

They also ended up with, in John Setka, another aggressive and divisive leader.

Australian Associated Press