Morrissey has penned an open letter on behalf of PETA to former Vice President Al Gore and Kevin Wall, co-founders of the annual Live Earth concert series, calling out the event -- which aims to raise awareness about climate change and environmental concerns -- for serving meat and dairy products.

“I am writing to ask you to do the one thing that will do the most good for the planet and the majority of its inhabitants: not serve meat or dairy products at Live Earth 2015,” Morrisey writes (via Rolling Stone). “I don’t mean offering a vegan option -- I mean not serving animal products at all.”

Morrisey accused the event of “greenwashing” by serving meat at its annual event and compared it to “selling pistols at a gun-control rally.”

“Your responsibility is to alert people to a crisis,” the ex-Smiths frontman continues, “not sell out to the vendors responsible for it.”

This year’s iteration of the event, “Live Earth Road to Paris,” will take place on June 18 just ahead of the United Nations' conference on climate change in Paris. The day will feature more than 100 artists at concerts across six continents.

The letter -- which can be read in its entirety here -- continues:

Since you can’t miss the fact that meat consumption is killing the planet -- your own sponsor organization, the United Nations, states this -- and since venues can and will cater vegan food for events, if you choose to serve animal flesh at Live Earth, you’ll be making a mockery of the very concept of the event, in which case it should be renamed ‘Dead Earth: We Contributed!’

Morrisey has been an outspoken animal rights advocate, and -- as he points out in his open letter -- requires all venues to become meat-free during his concerts.