If this Government did not maintain its doctrinaire, bigoted and ignorant prejudice against selective schools, the state system would produce many more students capable of thriving in the best universities. If such universities are forced to take a quota of pupils who are not academically up to it then those universities will decline. Standards would need to drop to avert a rash of failures. The best teachers, frustrated, would be driven abroad. So would gifted ex-private sector students, sent overseas by discrimination. Higher education would be added to the list of things we once did so well, but have through stupidity destroyed.Just as it has already done in the USA, from which the British slavishly copied their "comprehensive" schools. It's not just stupidity, it's also the cultural cringe that has infected British "progressives" since the early years of the last century, leading them to imitate every academic fad to emerge across the Atlantic.
Hilariously, the US Progressivism that the British Fabians copied was itself the ideology brought back from German universities by the first wave of American social "scientists" in the last decades of the 19th century. Not terribly surprising that "progressives" so easily default into totalitarian social engineering.