Trying to protect my pension

Advice needed.

My ex and I were together 19 years, married almost 16 and have one child (14)who lives with me. We always earned similar amounts but he chose to spend his money rather than pay into a pension. I was the one who always bought things for the house and paid all childcare costs. He bought a business in 2004 and we sold our house and used the equity to purchase house and business. This then failed and our house was repossessed, losing my £50k has now gone bankrupt without repaying any of his debts and moved far away so no longer sees his child (his choice and lack of effort). Having agreed that we would divorce on grounds of 2 years separation and no assets to split due to the debts and equity losses he caused me he has now decided to try and claim my pension. I have lost so much because of him that it seems very unfair that he can do this now. Our daughter is my nominated party in case I die in service so she is also at risk of being further disadvantaged by him.

If he had not worked and been a house husband supported by me then I would understand his entitlement but it was his choice not to pay into a pension for years despite my telling him he should.

Can I successfully make a case that any pension share he is due should be offset against the losses I have incurred due to him?

The counter argument will be though that you all benefitted from the extra money that didn't go into a pension at the time.

Was the house that was sold in his sole name or did you agree to invest in the business at the time?

Which I didn't because he never shared his money and spent it on himself and his hobbies!

The house that was sold was in both names and I never agreed to invest in the business. The business and house were attached but had separate loans - mortgage on house (joint) and loan on business (his name). All of it was lost when he failed to face up to the situation and ran away from it all without making any repayment arrangements or selling it before it could be repossessed