Slavery in the UK has nothing to do with austerity, as Dr Alf might imagine but rather is a function of wealthy people coming to London and employing Filipino and other foreign maids, nannies, housekeepers etc and keeping them in a state of indentured servitude.
The indigenous population elects not to do this sort of work and the public does not want to pay higher food prices.
Farmers on squeezed margins use the Gangmasters some of whom exploit the workers by enslaving them, beating them and paying them next to nothing.
The latest case featured in the Peterborough Evening Telegraph had Eastern Europeans chained up in shipping containers, beaten and paid next to nothing by dint of deductions for food from their piecework rates.
The UK Government knows this and it also knows that 250,000 illegal immigrants come here every year on top of the 262000 that came here legally. It cannot do anything about it and does not want to because these unfortunates grease the wheels of an economy in which the indigenous population is too lazy and unproductive to generate the nett tax revenues required.
The fact that UK worker productivity averages 40% or 88 working days out of 220 cannot be wished away.