Google's headquarters at Mountain View, California Getty Images

Tariq Yusuf, a privacy engineer in Google's Seattle office, is heading to Alphabet's Silicon Valley headquarters on Wednesday to take part in the company's annual shareholder meeting. But Yusuf is hardly attending as a cheerleader. Rather, he's part of a small group of Google employees attending the meeting to seek shareholder support for a diversity and inclusion proposal that the company recommends rejecting. The proposal, filed by Zevin Asset Management, which describes itself as a socially responsible investment firm, calls for Alphabet's executive compensation to be tied to gender, racial and ethnic diversity metrics in employee recruiting and retention. Zevin cites Google's own data showing that over the past four years, the percentage of women employees has only gone from 30 percent to 31 percent, while the number of underrepresented minorities has increased from 9 percent to 10 percent. "One of the reasons we partnered with Zevin is that it advocates building in the values that Alphabet purports to support," Yusuf told CNBC. Alphabet "can do a better job of putting its money where its mouth is to some degree," he added.

'Employees and investors locking hands'

Zevin's proposal challenges Google, which was one of the first major companies to publicly publish its diversity statistics, to step up its efforts and better protect employees working internally on diversity projects so that it has the talent to drive long-term shareholder value. Zevin has made similar proposals to Amazon and Apple. "It's not often you see employees and investors locking hands like this," said Pat Tomaino, Zevin's director of socially responsible investing. The Boston-based firm owns about $23 million worth of Alphabet shares, according to FactSet. Alphabet recommends shareholders vote against the proposal because the company says it already incorporates diversity values into its business. Because of Alphabet's dual-voting structure that gives the co-founders outsized control, the proposal likely won't pass.

Google founders Sergey Brin and Larry Page John MacDougall | Getty Images