My husband and I have our own bank accounts.
I pay half my salary into his to pay towards expenses.
He is now trying to put HIS so called savings into his own savings account , that he had in place before we were married , claiming it as non marital assets . Can he do this

We lived together for 16 years. Neither of us owned property. We decided to buy a house after 18 months together. He paid cash for it . His name on deeds only. £45k .
3 years later we sold it for £110k . Bought another house cash £97k again only his name on deed. We have now lived in this house for 11 and just got married . Is the now marital home still classed as non marital asset

Either one of you can do whatever you want with separate or combined accounts. Just be prepared and keep good records in case of divorce.

(Money he moves into an account while he is married isn't 'non marital' regardless of when he started the account.)

My new husband has made a will stating I only get a 1/3 of his estate when he dies. The rest goes to his children.
We have cohabited 16 years prior to marriage but everything is in his name , therefore classed as his estate where do I stand

I have merged all your threads together as they have a common theme.

Is divorce pending and hence the worry of this nature ?

No but I am concerned that as his children have already questioned his will that I am going to lose everything when he dies.

Are the years cohabiting taken into account in divorce , and contributions made in that time

As much advise too all questions would be appreciated .

What country?
You say 'we' bought and 'we' sold a house and bought another, but it sounds like the bulk of it was his? The house could very well be considered his if you get divorced or if he dies, if his will is the same when he dies. You need to sit down with a divorce litigator to determine how much you might get, regardless of whose assets are whose. We don't know how many expenses your half salary covers, for one thing.
Is it possible that your worries are not the usual ones about divorce, since you just got married? Maybe he is quite happy with you but just wants his 2 children to each get a third of his assets, which is normal enough. This is not to say you shouldn't be careful about record keeping.

Country England .
I earn the same as his combined income from his pensions . He is older than me .
I have no problem with him wanting to share his estate with his children . What I want to know is how much of what assets there is , is actualluy

All his to share , and what percentage of assets are mine as his wife . I also bought a property during our relationship which is in my name , but I class it as ours. I paid £35k from inheritance before we got married .

I hesitate to comment on English law. I'll just say again that in general, what is acquired before marriage is considered a non marital asset. This doesn't mean that divorce lawyers don't fight for more. Death is more precisely tied to what is stated in the will, and usually 'assets' are mentioned when it comes to real estate. I don't think you are going to get a share of any property in his name that was acquired before marriage if he dies. There's a much better chance of it if he divorces you, depending on your records and how good a lawyer you have.