can exp sell our house?

[spanisharmada]

Just looking for some advice, although I suspect I will need a solicitor.

Myself and exp jointly own a 3 bed house. When we split up he refused to leave, so myself and our 3 DC moved out. He has stayed in the house and rents out 1-2 of the bedrooms.
I rent a 3 bed house for myself and DC, ex see's them for a few hours one eve a week and one day on a Sunday. They do not go to his house he see's them at mine.
He has paid the mortgage on the house we own obviously, however my rent is 1.5 times as much, I need 3 bedrooms for me and DC. He doesn't which is why he rents rooms out.
I have been given notice that we will have to move early next year. ExP is apparently planning to move away from the area, he plans to sell the house and keep all/any proceeds.
Can he do this? Does he need my agreement? Would I have a case to argue myself and DC should be able to occupy the property if he vacates and moves away?

I'd really appreciate any advice.
Thanks.p

1. He can't sell it without you.

1. Under the Children Act (Schedule 1) the court can allow you to occupy the property with the children, to his exclusion, until the children finish their education.

1. If you have evidence of his intention to sell and move away, then that's even better. You'd expect him to tell the judge on a Children Act application that he wants to remain living in the house himself.

Thank you that's really helpful