Or he'll meet another woman who's willing to do all of the parenting.
I see where you're at OP. You're very unhappy in the relationship and the cleaning has highlighted to you how disrespected you feel.
It's really hard, without knowing a relationship well, what the best course of action is. Because I don't think it's always a case of, doesn't pull his weight = doesn't love you. Some people just have lower expectations and lower abilities to keep on top of chores. I've seen it with the difference in lifestyle of friends; some keep a top house but something else gives. Others have low standards around the house but high stress jobs for example.
It's also hard to know how big the issue is without knowing how else the relationship plays out. You mention you work more hours, does he do more childcare? Who looks after the car, DIY, holiday planning, finances etc (all rhetorical).
I think it's also worth noting that there aren't perfect people out there. That's not to say you should end the relationship over this, if it's really getting you down, and he won't change, then yes, you deserve to be happy. Just go onto a divorce with your eyes wide open. You may meet someone else, but they won't be perfect. And if you don't want to meet anyone else, aspects of life will be tougher.
I'm it trying to put you off leaving, but just don't get caught up with Mumsnet - it's great for some things and very off on others. I guarantee you that most women here have issues with their partners, unfortunately that's part of long term relationships (and that's not an excuse for men, women can be pretty shit in lots of ways too).
Ultimately though, you know how you feel and how your relationship is day to day. Perhaps a counsellor for yourself can help you gain clarity over the situation before making any drastic decisions.