“You don’t need to know” is a pernicious and provocative statement. It expresses arrogant authority: “I have the good judgement required to make my decision based on the facts. You don’t have that kind of judgement: you should just trust me.” Argue and this turns into a fight about why you are disrespecting the Authority by refusing to trust their good judgment, though the first act of disrespect was denying you the facts.
The Freedom of Information Act opens up all levels of public infomation to the public. The standard of the Freedom of Information Commissioners is that all information should be made available, with clearly specified exemptions to do with personal privacy and national security: there is a legal exemption if someone has asked for information that would be too expensive or too burdensome for a public body to provide, but they have to prove this to the Commissioner – they cannot simply tell you “too expensive, we won’t tell you”.
You don’t have to say why you want to know. You don’t have to prove “Need to know”. You don’t have to demonstrate that you have the good judgement to use the information wisely.
You are a member of the public. You want to know how a local authority or a public body arrived at a decision, or what they spent money on, or what was minuted at a meeting, or what the borrowing records are at your local libraries. The Freedom of Information Act says that wanting to know means you have a right to know.