"Pack your shit and fuck off, cunty bollocks" should cover it!
Tempting ;)
OK, pick very bland statements that he cannot argue with or refute, and just keep repeating them. Don't talk about his behaviour, just continue repeating along the lines of "This relationship isn't making me happy, so I'm ending it. Please get your stuff together and go back to your mum's."
If he starts crying about "I can't go to my muuuuuuum waily waily" then just keep repeating "You need to make arrangements elsewhere then, as I need you to move out today."
Get your locks changed as soon as he's gone. Don't trust him to give you his key back.
I repeat, don't say ANYTHING that gives him a chance to dispute. Just stick to talking about YOU and the decision that YOU have made. He is not entitled to an explanation or justification. You have decided it's over, that's all he needs to deal with. Just stick to your line of "I've made my decision and it's not up for discussion."
Good luck, I know it's really hard but it's so worth it to get your calm, happy home back with you happy and focussed on your DC.