I think Lammy is wrong and right. There certainly is a problem with representation of working class/ethnic minorities at Oxbridge, but it isn't the fault of Oxbridge if applicants from these backgrounds don't have the academic record. They can't accept people who they aren't sure will be able to keep up with the rigour of Oxbridge because that damages the reputation of the university; correct me if I'm wrong, but TEF take pass rates/degree classification into account, don't they?
The problem is that private school students or middle class white children from the South have an advantage from the very beginning. They're brought up by educated parents who make sure they send them to better schools, they're socialised in the 'correct' way, they're brought up with a standard of success and have scholastic and professional opportunities that working class students (particularly minorities) do not. We cannot keep pretending like environment isn't important, and we certainly can't pretend that our society is in any way authentically meritocratic if we don't acknowledge that some kids have a far better chance of getting in because of their upbringing compared to their working class counterparts. Instead of forcing Oxbridge to become more lenient, we should be setting up schemes to encourage, incentivise and enable working class children to pursue Oxbridge from the minute they get to secondary school. I only learned about university and A level requirements in my last few months of AS - and that was far too late.
But more than just getting academic levels up to scratch, we need to teach working class students to cope in middle-upper class environments. When I went to university and started to socialise with people from middle class backgrounds, I **** you not, it was like moving to another country. The culture shock was immense, and I don't even go to an incredibly impressive university. The alienation that ethnic minority and working class students must feel at Oxbridge is probably far worse. Teachers in working class communities, though some are good, a lot more care about spoon-feeding kids and getting them to just pass. It's a numbers game where they care more about their own annual performance evaluations than encouraging their students, and I don't blame them. But being told that you should be aiming for Cs when you know you can achieve As is demoralising. Working class and ethnic minority kids need to be taught to speak properly and with confidence, they need to be taught how to behave in certain social settings and network, as their middle class counterparts have. This, alongside academic performance, will help empower more working class students to apply to Oxbridge.