A $50,000 contribution from a metalworkers' union to Australia's Labor Party has focused attention on a long-simmering issue here: the power of labor unions.
Prime Minister Malcolm Fraser's Liberal Party has pointed to the size of the metalworkers' contribution - and to the level of strikes here - as proof that unions are too powerful.
Mr. Fraser holds that union strike activity and the winning of high wages have damaged the nation's economy - so much so that he says port strikes have given Australia a reputation as an unreliable supplier. Japan, in particular, has speeded up its search for other exporters of coal and wool.
Noting that Labor Party leader Robert Hawke is a former president of the Australian Council of Trade Unions, the prime minister suggests that if Labor wins the March 5 election, the unions may become even more powerful.
In campaign literature, the Liberals refer to the metalworkers' contribution to Labor, saying: ''It cost the metalworkers $50,000 - how much will it cost Australia?''
Fraser says that if he is reelected, his government will hold a referendum on curbing union strength. He proposes several laws in the next session of Parliament that would:
* Outlaw strikes unless union members vote by secret ballot to strike. The government argues that such a law would cut down on a tendency to intimidate workers to support strikes when the voting is by a show of hands.
* Provide for government supervision of union elections to ensure voting procedures are honest.
* Allow the government to continue essential services when these sectors are hit by strikes. The government notes that transportation systems, telephone service, and telex have all been crippled by strikes from time to time. In his election campaign, Prime Minister Fraser has suggested he may import drugs from overseas to ensure that a threatened pharmaceutical industry strike does not leave hospitals without drugs.
The current head of the Australian Council of Trade Unions, Cliff Dolan, says Mr. Fraser's proposals constitute ''union-bashing.'' He suggests that such laws would cause more strikes rather than bring industrial peace.
Although unions are unpopular with the public at large now, they are extremely important in this country. Most workers are unionized.
Australian unions range from huge and powerful organizations such as the Amalgamated Metal Workers' and Shipwrights' Union and the Storemen and Packers' Union to small, weak unions with relatively little clout. (Some small unions, however, have considerable power if they are in critical sectors.)
There is sometimes a show of solidarity among the unions. Police and Salvation Army volunteers, for example, feed convicts when prison personnel strike. Gravediggers refuse to work when burials are handled by cut-price funeral companies.
Today, many unions are riled over a six-month pay freeze and are organizing to stop it.
Most unions work for the Labor Party, and while there are unions that support the right wing and main-stream of the party, other major unions are communist-led.
In the construction industry, for example, one big union is led by supporters of a Moscow-line party and another by supporters of a Peking-line party.
The communists seem to be divided into factions that are not very friendly toward one another: pro-Moscow, pro-Peking, Trotskyists, supporters of the ''independent'' (similar to Eurocommunists) communist party of Australia. Within even these categories there are splinter groups. Among pro-Peking communists, there is a group supporting the present Chinese government, another that is Maoist, and even a few pro-Albanian ''purists.''
But these distinctions mean little, most labor union analysts say, to the average worker in a recession-hit but still relatively affluent free-enterprise society.
Many union members would not ordinarily vote for communist leaders, analysts say, except that they are seen to produce results: more pay, shorter hours, and better working conditions. Many of the unionists would not vote communist in national, nonunion elections, they say.
Prime Minister Fraser, who says the March election ''is about responsibility, '' is gambling on popular support from a regularly inconvenienced public in his effort to do what no Australian leader has managed before: taming the unions.