This year's gloobal shipping situation is grim, partly due to the port congestion caused by the strike. Disputes between trade unions and employers are the main reason.

It is understood that due to a long-term dispute with the employer "Svitzer Towage", three maritime trade unions in Australia will hold a strike.

This will expose nearly 10 ports in Australia to the risk of interruption of operations.

Svitzer is one of the major tugboat operators in Australia. Since signing a contract with the trade union in 2016 and the contract expires in 2019, it has not signed an enterprise agreement with the trade union.

There are three independent trade unions behind the strike: MUA, AIMPE and AMOU. In more than three years, they held more than 50 meetings to try to reach a new agreement with the trade union.

When the shipping companies have been facing the huge pressure of the continuous supply chain crisis, this will make the ships from Cairns to Melbourne and then to geraldon only get limited tug services.

The tugboat company svitzer said that all ports where the strike occurred on Friday were expected to be disrupted, but the situation was particularly serious in Brisbane and Melbourne, where workers were suspended for 24 hours.

In addition, workers from eight other ports participated in Friday's strike, including Cairns, Newcastle, Sydney, Kenbla port, Adelaide, Freemantle, Geraldton and Albany port.

A four hour strike is expected to start at 9 a.m. local time. However, they said that they would continue to provide tug services for naval vessels and cruise ships during the strike.

"Svitzer is doing its best to minimize disruption to customers, the port and our operations," a company spokesman said

In a statement issued by the MUA trade union, they accused svitzer of being insincere in the negotiations, "putting forward a series of unreasonable demands and threatening to reduce the wages of its port workers by nearly 50%."

A spokesman for svitzer responded to the Union's allegations, saying that the company had offered to "maintain wages and core conditions" as part of the new contract. They believe that the deadlock is about the refusal of trade unions to "reasonably increase productivity".

Paddy crumlin, the National Secretary General of MUA, said: "svitzer's aggressive brinkmanship may cause complete chaos to the smooth and efficient operation of almost all Australian ports."

The union said that the action plan expected by svitzer would destroy workers by cutting their wages, causing them a great risk of fatigue.

At the same time, they weaken the ability to provide reliable and efficient tug services to international shipping companies and port authorities.