I'm a dependent student but my parents aren't too keen on signing their details

My parents, who I live with, no longer financially support me but I'm 21 so I am still considered a dependent student as I only started work 2 years ago. I was on jobseekers allowance but that was still less than 3 years ago. They want to know what they're signing, but it can take 2 months to process my application so I'm not sure if they'll sign it or if when they do, it will be before I start my university course. I'm not sure if I have any options here. I am only applying for the tuition fee loan as I am an Open University student, so I'm not sure if this will affect my application?