Mozilla employees are calling for new CEO Brendan Eich to step down over his support for the Proposition 8 campaign that opposed same-sex marriage in California.

As Ars Technica reports, Chris McAvoy, project lead for Open Badges at the Mozilla Foundation, tweeted his disapproval of the appointment earlier today. It triggered a number of similar responses from other staff at Mozilla, perhaps planned, asking for Eich to resign from his new position.

Back in April 2012, it was revealed that Eich donated $1,000 to the Proposition 8 cause. Following his appointment as CEO on Monday (March 24), the former Mozilla CTO issued fresh commitments to reassure his critics.

“I know some will be skeptical about this, and that words alone will not change anything,” he said. “I can only ask for your support to have the time to ‘show, not tell'; and in the meantime express my sorrow at having caused pain.”

Eich is yet to respond to today’s backlash on Twitter. We have reached out to Mozilla for comment and will update this article if they respond.

Update: Mozilla has offered the following statement from Mark Surman, executive director of the Mozilla Foundation.

“Our culture of openness extends to letting our staff and community be candid about their views on Mozilla’s direction. We’re proud of that inclusiveness and how it distinguishes Mozilla from most organizations. We expect and encourage Mozillians to speak up when they disagree with management decisions, and carefully weigh all input to ensure our actions are advancing the project’s mission.”