Australian's powerful labor movement today adopted a policy toward the nation's vast untapped reserves of uranium that guarantees confrontation with the Australian government and could trigger an early general election.

The national congress of the Australian Council of Trade Unions voted overwhelmingly to demand a national referendum on the future of Australian uranium. Prime Minister Malcolm Fraser has already indicated that he would not hold a referendum on the controversial issue.

Japan and several countries that are planning to supply their future energy needs with nuclear fuels have been putting intense pressure on Australia to open up its uranium reserves.

Recent Australian governments have delayed the decision pending a study of how this would affect the environment and the aborigines in the mining area. Concern about possible diversion of the uranium byproducts into nuclear weapons was also a factor in holding up the decision.

In a rare but not unique flexing of muscle in a country where union power equals and frequently surpasses the power of Parliament and the courts, the union confederation said that if the government does not agree within two months to hold a referendum on the issue within a year, unions would threaten a work boycott on any new development of Australian uranium reserves.

Prime Minister Fraser, a conservative, has not yet commented on the Congress' vote, but he has left no doubt that he will refuse to conduct a referendum. If the union movement carries out its threat in two months' time to bar uranium development, Fraser is considered likely to call a parliamentary election before the end of the year - 14 months ahead of time.

Fraser and his senior ministers and advisers have left no doubt what their campaign issue would be - who is running the country and making major national decisions, the elected government or the unions?

Delegates to the union congress voted 493 to 371 in favor of a referendum.

Significantly, a coalition of Socialist, Communist, environmentalist and emotionally anti-uranium delegates defeated the traditionalist car within the Australian laor movement - those delegates who voted for developing the country's uranium because it would create jobs and boost Australia's trading wealth.

There is no doubt that Fraser would like an early election.

Australia's stagnant economy, which he promised to revive when he was elected over Socialist Gough Whitlam in a landslide in December 1975, is no better and in my respects worse than it was then, and is expected to decline further next year.

Unemployment is now 5.5 per cent - one-fourth higher than two years ago; inflation still hovers at nearly 11 per cent and despite a massive devaluation last November, Australia's reserves and trading terms have been declining steadily.

Today's union decision many have handed Fraser and his conservative coalition of Liberal and Country parties an election issue that could insure their continued hold on power.

Last month Fraser announced his government's decision to go ahead with the mining and export of Australia's huge uranium deposits - about 30 per cent of all uranium reserves in the non-Communist world and worth more than $30 billion at current market prices.

Fraser's decision was based on recommendations growing out of three years of detailed examination of the issues by a commission set up by the previous Labor governments.

Stringent environmental safeguards were laid down.

The nomadic aborigines - now only about 800 of them - who roam that area in northwest Australia, where the huge uranium deposits lie, will get huge royalties and the right to own much of the land surrounding the mines. Fraser laid down safeguards against misuse of Australian uranium or its byproducts by customer nations. He claims that the restrictions are the most stringent in the world.

Fraser also pledged to co-operate with the United States and Canada - which, with Australia, own more than 80 per cent of the Western world's uranium - to establish safeguards against nuclear-weapon proliferation and misuse of uranium bought for peaceful purposes.

The union confederation's decision to push for a referendem was brought about by the group's powerful and ambitious president, J. Robert Hawke. He sought to head off a move by the more leftist unions for an immediate work stoppage.

Nevertheless, opinion polls show a solid majority of Australians in favor of uranium development, and Hawke's maneuver for a referendum will probably fail and, at thesame time, aggravate voters.