FMH sold, Can I refuse to leave?

I can see your position and agree that you have to use any lever you can to get what you can.
As said it may depend upon whether you signed to agree to leave or not and my suspicions are that as the property has gone to exchange that you did. Any buyers conveyancer would or should have held up an exchange if there was doubt that you would leave as it would mean (technically) that as your x is sole owner he could have control over the sale.
The buyer would however find that the house was not being sold with vacant possession and they couldn't move in . This would cause untold problems for the buyer ie they could be homeless.

Just for your info exchange is when all documents are formally exchanged between conveyancers and the buyer is locked into the deal and cannot escape without penalties. That is why a buyer insures the property from the date of exchange.
Once exchanged its usually a case of days or a couple of weeks before completion to allow for tidying up loose ends ie mortgage funds release or to coordinate everyones moving date if there is a chain.

Im only going on info you supplied and your solicitor should advise you.

I've since got a second opinion from a no nonsense solicitor. I'm going to register MHR and threaten to halt completion until an interim agreement is made.

Im aware of the issues for the buyer. And I have made the agents aware of the situation. Unfortunately my priority right now is to my children. An I will to use whatever legal means I have to secure maintenance. We have enough funds to compensate the buyer should my ex continue to be unreasonable.

I'm aware of the process of exchange and completion. This is a very unusual situation. The offer was made and accepted on the FMH in August 2016. At that point we weren't divorcing but our intention was to allow enough time for us to find a new home. (Houses rarely come up in the quater of a mile radius to school) Exchange took place in mid February and completion tied in with the end of the academic year.

Good !! You found your solution and I have lived by the motto;

''There are no problems, only solutions but you have to search for them''

Thats what wiki is here for..bouncing around ideas between people who are either in or have been though the process.

Sorry if I expanded on some points but many people don't actually know full processes of house purchase and sales.

Im surprized that your buyer isn't kicking though but of course the process was at a price locked some time ago and is probably beheficial to them.

Good luck

Polar

Thank you Polar, I appreciate the advice, I hadn't considered they'd be others possibly facing the same situation. It's a very lonely experimace this divorce thing. Anyway what will be will be. I will be applying for consent to move 50 miles away too so a long process ahead.