Can cost of drawing up a will ever be, in part, a business expense?

Client has paid to have his will drawn up. Most of his assets are his business. He is adamant that this is a business expense (for both income tax as sole trader, and VAT) - despite me saying the contrary. I can't really see my way to agreeing with him, even in part.

On the other hand .... if it was advice on the sale of his business, I suppose that would be deductible and, at a stretch, disposition on death is akin to a sale. What does the team think?