It is very doubtful that he will leave just on your say-so.
He won't want to lose the relationship or his comfortable home - he's not the one having to climb into bed with the person who flings stuff in his face, after all...
What he will VERY VERY likely do is do his UTMOST to manipulate you into letting him stay. Not by intimidating openly - he wouldn't be so stupid as to push you over the edge right now. He knows he's on a knife edge.
What he will do is use any means of persuasion and manipulation to get you to roll over. Poor me. Let us try again. I'll be homeless. I didn't mean it. I'll get counselling. I love you, you can't give up on us. You're mad. You're totally overreacting. Just one more chance. I didn't know what I was doing. Etc.
And he knows you. He will be able to SMELL your confusion and vulnerability right now. He's going to use it to the max. His aim will be to get to stay in your home, stay fed, stay watered, stay housed, stay serviced.
PLEASE tell someone. That's what will shoot him down. If you can't speak to friends, PLEASE call 101 and speak to the DV officer.
It might be that just letting him know that you've done this will beat him - he'll know his number's up.
It might be that he continues to hassle/avoids leaving - hmm, what are you going to do, FORCE him out of the door with no bag? Not likely - in which case, you can get a police officer to come round and MAKE him leave.
Please think about this.