Put it this way, if there is any possibility you want to be a commercial lawyer in the future at a big city firm this is what you need;
Good GCSE's (A*-B grades) + AAB or above at A level + a degree in a respectable subject from a Russell Group university or Oxbridge (being a 1st or a good 2:1) + lots of extra curricular + vacation schemes at city law firms + fierce determination
I think you get the hint on what unis are acceptable. Law is a dog eat dog degree and a cut throat profession, pick wisely.
Note city law firms also have A level filters, few ABB the rest pretty much AAB.