How can I know whether I meet the minimum standard to be guaranteed a place on the course?
You can’t know this, because selection for the course is competitive, and so your chances of being selected must depend to some extent on the strengths of the other candidates who apply. In practice, we very seldom admit candidates with lower-second (2:2) class degrees; usually about half of our successful candidates have first-class degrees, and about half have research degrees of some kind; about a third have upper-second (2:1) class degrees with no research history. But academic history is not the only criterion we consider: a first-class degree will not guarantee you a place, and a 2:1 does not mean that you have no chance of success. It’s worth mentioning that some of our best students on the course have arrived with 2:1 degrees and no research degrees.