I don't know why you fantasise about discriminating against productive law abading EU citizens. I guess you personally are better of out of EU and EU is better of by not having you. It's very creepy that you are annoyed that you can't arbitrarily discriminate against EU citizens.
Also, there's no such thing as a low-wage Eastern Europeans, they still rent in UK and shop in UK and are employed within the UK labour laws. If you are against low wages you should increase the minimum wage, if you can't compete against Eastern Europeans it's because you don't provide enough value to the employer to choose you. If British are outcompeted in the labour market, maybe British should re-evaluate their education system. British employers don't hire Bulgarian butchers when they need JavaScript developers just because it's cheaper to hire Bulgarian butchers. It simply means that Brits don't have the skills for the money they ask, the Eastern European ones have it and that's why they get the job at free market rate.