Can novelists claim benefits such as jobseekers allowance?

I'm hoping to be a writer one day. But my brother told me that if any of my work gets printed, I will never be able to claim unemployment benefits because, even if one book sells a month, it would be still cled as income (even though its pittance). This is scary as creative writing isn't necessarily a stable source of money. Is there any truth to this? I reside in the UK, Northern Ireland, if this is of any relevance. Thanks :)