The teaching profession in Britain should concentrate on attracting top graduates at the expense of those with lower-level degrees from lesser universities, according to Conservative party leader David Cameron.Launching the education section of his manifesto, Cameron said today that a future Tory government would require aspiring teachers to have a 2:2 degree or above to qualify for training funding. Moreover, graduates who achieve a 2:1 or above “in a rigorous subject from a good university” could apply to have their student loans written off, in a move which could be expected to deter those who do not fall into that category.