The investment fund of a major union activist is targeting the pay packages of two major pharmaceutical companies.

The American Federation of State, County and Municipal Employees (AFSCME), the largest public employee and health care workers union in the United States, is recommending that shareholders of both Pfizer and Johnson & Johnson vote against the executive compensation proposals at the annual meetings of both companies, which take place on April 28.

It's all about pay.

When shareholders gather at this year's annual meetings, executive compensation figures to be the number one issue on the proxy. This is partly because the Dodd-Frank Act requires all companies whose annual meetings take place after January 21, 2011 to hold so-called Say on Pay votes on their Compensation Discussion and Analysis (CD&A)-an advisory non-binding up-or-down vote. They also will be required to vote on whether the company should hold future votes annually, bi-annually or tri-annually.