The International Association of Machinists will ask the Federal Election Commission today to crack down on federal campaign contributions from corporate political action committees (PACs) on grounds they are not truly voluntary.

In a reverse twist on business complaints that unions have taken unfair advantage of campaign gift-giving laws, the machinists' union alleges that corporate PACs amount to a "system of kickbacks from employes not in a position to shrug off company requests for support."

The IAM, in a formal complaint that union officials said will be filed today, asked FEC to find that corporate PACs are operating in violation of federal law and to provide "appropriate remedial relief."

The union charged that employes solicited for PAC contributions are mainly "career workers whose advancement is entirely dependent upon maintaining the good will of the employer," and contended that these workers are protected neither by union job-security guarantees nor by assurances of anonymity.

It also argued that rights of corporate stockholders are violated when company assets are used to pay operating costs of the PACs and that stockholders have no voice in deciding which candidates are to be supported.

If the FEC decides that corporate PACs are operating within the law, the ban on direct union contributions to political candidates should be lifted, the IAM said. Unions, like corporations, are banned from making direct contributions to campaigns but may channel voluntary payments through separate committees.

The IAM cited the 10 largest PAC committees -- involving Dart Industries, Eaton Corp., General Electric, General Motors, Winn-Dixie, Standard Oil of Indiana, Union Camp, United Technologies, Union Oil and International Paper -- as examples of what it called "coercive" fund-raising among employes.

It said they provide "no arms-length protections, against compulsion" and even permit personal solicitations by an employe's immediate supervisor.

It said Justin Dart, chairman of Dart Industries, personally contacts employes who have not contributed. Eaton Corp., the union added, advocates "face-to-face" meetings of managers and employes to get contributions.

In all cases, the IAM contended, average employe contributions far exceed normal political contributions. While the average annual personal gift to political candidates and causes is $16, according to the union, the average corporate PAC contribution ranges from $116 to $338. Most corporate PAC money, it said, is spent in states other than where it is raised.