on (one's) conscience
Causing one persistent, nagging guilt for something one did or failed to do. It's because of your cruelty that your brother died. I hope you have it on your conscience for the rest of your days! I really regret the way I treated her in high school. It's still on my conscience to this day.
on your ˈconscience
making you feel guilty for doing or failing to do something: I’ll write and apologize. I’ve had it on my conscience for weeks. on (one's) conscience
Causing one to feel guilty or uneasy.