You ask £40k and 1.5%. What's the worst that can happen?
well the worst that can happen is that he does not get hired: no salary increase, no equity. And this is not even the worst that can happen. I have withdrawn (let them expire) offers from people that after receiving my first offer tried to strongarm ridiculous bonuses. The reason I have withdrawn the offer is that it made me clear that the person does not understand their worth to us - hence would likely be a trouble…
I asked for fair market value, i.e. I understood I was asking for less than my value to the company. When this elicited a bitchy response along the lines of what you have said, I understood enough about the company to find a better job.
Companies that won't negotiate with you over salary, won't negotiate with you over anything. A toxic place to work.