Are you living together now?
If you are married they will say you are sharing expenses even if you are not living together on the face of it.
That will mean you will have to declare his income and that will probably have an impact upon a means tested benefit like ESA.
There isn't really a way around it.
If you are married to a person earning £1500 a month then you cannot claim ESA I'm afraid.
Sorry if that is bad news.
Can I clarify anything for you?