"Surplus labour creates low wages and zero hours contracts."

This is simply not true, and, worse, it is one of the stock racist excuses for keeping immigrants out. Low wages are created by employers paying low wages because they can. Get it? Zero-hours contracts are created by unscrupulous employers who have bought into the Tory lie of the "flexible labour market." Yes there is a minority of workers who put on a brave face to say that those contracts suit them. The truth is that those contracts are one of the most iniquitous developments of modern capitalism, the legacy of the emasculation of the trade unions, started by Thatcher and gleefully perpetuated by New Labour. Corbyn's Labour has promised to get rid of zero-hours contracts. I disagree with almost everything that Corbyn is doing apropos of brexit, but that's one thing I mightily applaud.