For some, robots may be the most likely replacement, according to a report by the Resolution Foundation think-tank.

Almost one third of the workforce in food manufacturing are EU migrants. More than a fifth of domestic personnel are from the EU, and more than one in eight workers in sectors ranging from agriculture to warehousing and textiles manufacturing.

An end to free movement of labour would – other things being equal — make it more costly to fill these jobs. Given other changes such as the living wage, auto-enrolment in workplace pensions and the apprenticeship levy, there will be a strong incentive for employers to invest in automation.

This does not have to be a bad thing, the think-tank argues. The ready supply of cheap workers has allowed UK employers to get away with relatively low levels of capital investment for many years, a trend that has become even more evident since the global financial crisis.