Degree or no degree....
I believe that the RAF is currently changing its preference here as a result of Typhoon and JSF coming into service. There is now an in service degree system in place which allows you to build up points towards a degree as you go through various aspects of your in-service training. The idea is that a young lad straight from school hits flying training at the best age to learn the new skills required of a modern generation fighter pilot ( no longer how many ales that could be sunk in the bar the evening before a 4-ship) Best to investigate the scheme on the website and then ask your friendly Careers Office advisor who may just know about the scheme.
The cynic in me would also say that the young lad will be more likely to give a good return of service and be more inclined to accept the fu%^ing around than an older graduate who is nearer the age of settling down and having family ties etc.
Best of luck with the Careers Office, the advice that I was given first time around was not the best for me but the best for the service needs. Things may have changed now.