BOSTON (AP) — A group of Christian, Hindu, Buddhist and Jewish leaders is asking Starbucks to stop charging extra for vegan milk alternatives.

The interfaith coalition says the practice amounts to a tax on people who’ve embraced plant-based lifestyles.

The group’s leader is Nevada-based Hindu activist Rajan Zed.

He and the other clergy members pressed the coffee chain on Friday to end the surcharges they’re calling “unethical and unfair.”

Starbucks outlets in the United States typically charge 50 cents to a dollar more for drinks made with plant-based milk.

Seattle-based Starbucks did not immediately respond to a request for comment by The Associated Press.