As previously reported by DS, the pair - who play Zoe Carpenter and Sarah Barnes respectively - will bow out of the Channel 4 teen soap later this year.
One of the girls' exits, however, will result in a "tragic curtain call".
Speaking of her decision to leave, Lister said: "I've had a fantastic time in the show and have worked with some amazing people! I'm very sad to leave but feel that it's time to try new things."
Batley commented: "I've learned so much, met lots of lovely people and made some incredible friends. It's been a massive part of my life and will be a sad chapter to turn the page on."