Ask an Immigration Solicitor. Get an Answer ASAP.
Thank you for posting your question on JustAnswer. I am reviewing it and will reply ASAP
You are considered a British citizen if you were born in the UK before 01/01/1983. You need to explain the reason you do not have your father's passport. If your father was in the UK on an official mission, have you explored the possibility of obtaining a copy of his passport from those who sponsored his official mission?
The alternative is to apply for Judicial Review through the court if you are refused a UK passport.