Both unions have a similar philosophy and approach to workplace relations. Indeed the MUA has been particularly militant in the oil and gas sector over the past few years.

From the mining sector’s point of view, particularly in the west where unions have been largely irrelevant, the merger poses particular problems.

With bulk commodities such as iron ore there is a simple truism to industrial relations negotiations – control the ports, control the argument.

That is what the unions did in the 1980s during the battles at Robe River.

Without the port the iron ore could not be sent to market, putting the company at a disadvantage.

However, the tactic did not work out for the unions there because there was a change underway in society at the time and people were getting a little sick of the liberties unions were taking.

Serving the same flavour of icecream two days in a row in the canteen was enough to create a general strike.

In fact the industrial strife at Robe River effectively broke the unions’ hold on the Pilbara and they have never quite been able to get themselves re-established there.

According to the unions themselves, the potential merger will create Australia’s most powerful union, to better serve the memberships of both.

“We have been presented with a monumental opportunity to represent working men and women in the Australian workplace without losing the long and proud history of our union,” MUA national secretary Paddy Crumlin said.

“The MUA is no stranger to mergers and since the Waterside Workers’ Federation and the Seaman’s Union of Australia amalgamated in 1993 the UMA today is here to stay and can only grow in strength in this new union.”

CFMEU national secretary Michael O’Connor said the opportunity his union had been presented with would bring great strength to the national and international union movement.

“The MUA offers us a chance to strengthen our politics within the CFMEU because the struggle isn’t about increasing wages or creating a safe work site, there is also a bigger and important political struggle,” he said.

Australian Mines and Metals Association chief executive Steve Knott said there were reasons to be concerned.

“The merger would see the coming together of Australia’s most lawless union – the CFMEU – subject to increasing censure from our courts with a union, the MUA, publicly committed to breaking the law when it deems necessary,” he said.

“This would see the creation of an organisation with deep pockets but very shallow respect for the law, which is likely to pursue outdated workplace relations strategies calculated to cause maximum harm to employers regardless of its impact on our economy and community.

“Unions repositioning themselves and recasting their structures to become more effective, demand more effective regulators to wage the continuing battle of seeking our laws are observed in construction and maritime workplaces.”

Knott said the MUA-CFMEU merger only increased the need for the Senate to approve legislation to create a specialist body to better regulate the financial oversight of trade unions and to fully restore the Australian Building and Construction Commission.

“Such legislation is aimed squarely at ensuring unions use members monies appropriately with sound governance oversight in addition to conducting their business in accordance with Australian law,” he said.

“When last in existence the ABCC was instrumental in ensuring increased productivity on major construction sites, ultimately saving consumes and shareholders billions of dollars.

“It belies belief that the findings of the Trade Union Royal Commission together with numerous rulings against union misbehaviour and militancy in Australia has not been enough to generate support for these important and necessary changes.

“The addition of a potential merged ‘super militant union’ into this environment, formed from those who often have been found to have little          regard for the rule of law, only strengthens the case for greater regulation of union finances and activities, more transparent and effective governance standards and harsher penalties for those found breaking the law.”