Are you funded by anyone (university, research council or a private company)? If so, your bank would understand your situation. Did you speak to the manager? Or, if you are applying for an online loan, don't tick the student box (because they will assume you haven't got a regular income) but tick the "employed" or "other" box and state that you are a PhD researcher / doctoral student. It's only £1000, so your income (if you are funded) should be enough for that amount.