Japan's robots may pay union dues . . . but will they attend meetings?

If robots are to replace humans on factory assembly lines, shouldn't they be union members?

One Japanese union thought so and the company management agreed. But they immediately ran into a government ruling that ''only humans can belong to a labor union.''

The idea cropped up when the Fujitsu Fanuc Company established its much-publicized automated robotmaking factory at the foot of Mount Fuji two years ago.

No worker layoffs were planned, so union leaders assured the management they would not oppose automation - which comes into its own on the night shift when not a single human is on the premises. As a result, there are some 200 sophisticated robots virtually recreating themselves around the clock.

After their initial acquiesence, however, union leaders began to do some basic arithmetic. They were shocked when the company announced plans to build more unmanned factories.

With the human work force remaining static while productivity has increased rapidly, Fujitsu Fanuc's sales have increased sixfold in the past two years, generating huge profits.

By comparison, however, the company union's finances have gone from bad to worse. Members pay roughly 1 percent of their net monthly income, without overtime (in some companies it is as high as 1.5 percent) which for an average worker in his 30s would mean a contribution of about $18 to $20.

From this money, the union's full-time officials draw their salaries, pay all operating expenses, and make contributions to national union federations.

Union chairman Takatozu Suzuki commented: ''We only have about 700 members now, and there seems little chance this number will increase. In fact, with normal wastage the human work force could shrink until very soon we are outnumbered by robots.

''When the management established this unmanned factory, we were not opposed because we could see the rationale of automation. But union finances were in deep trouble, and management readily agreed that the company would pay union fees for every robot to help us survive.''

But no money has been paid because of government opposition.

''Robots are not considered human,'' declared a senior official of the Ministry of Labor. ''If fees are paid into union funds on behalf of robots, that would be defined as financial assistance from the management, which is illegal in order to preserve union independence.''

Union chairman Suzuki is determined to lobby the Diet (parliament) for a change in the law, especially as more and more small company unions are likely to face the same problem with growing automation.

''One robot should be made equal to at least one human worker as far as union membership is concerned,'' he said. ''In fact, as management always maintains that one robot can do the work of five men, it should pay union dues five times larger. . . . Then we can get out of our financial difficulties.''