Both our names are on the mortgage, and there's been some big bust ups and I want to get the house sold but he is refusing to sell up.

Doesn't matter whose names are on the mortgage, it matters what names are on the deed.

If he is refusing to sell then ask him to buy you out. If he won't do that, then you may have to sue for a partition.

Are you divorced or in the middle of a divorce ?
Has a court order given you the home ?