BY RIGHTS, the general manager of the Royal Lancaster shouldn’t have much to worry about. With sweeping views over Hyde Park and a glitzy history of hosting footballers and pop stars, the posh central London hotel has ticked along nicely since it opened in 1967. Now, however, Sally Beck has a headache: Brexit. And, specifically, how she will keep going if that means losing unfettered access to workers from the European Union. Like many hotels and restaurants, the Royal Lancaster depends on migrants. About half its staff, including a third of its managers, were born in continental Europe. These proportions are common in the capital, and even in the regions can be as high as 40%, says Ufi Ibrahim, the head of the British Hospitality Association, a lobby group. Overall, the hospitality industry—the country’s fourth-largest by income—employs 4.5m people, of whom at least 700,000 are from the EU.

Other industries are similarly reliant on EU workers (see chart). Jack Semple of the Road Haulage Association, an industry group, estimates that Britain has 600,000 licensed lorry drivers, of whom at least 10% are from the EU, mostly the eastern part. In agriculture the proportion of EU workers rises in the summer, to pick fruit and vegetables. There are also large numbers working in health and social care. Overall the total of EU citizens in Britain more than trebled, from 0.9m in 1995 to 3.3m in 2015, following the accession of 13 new countries to the EU after 2004.

For some industries it is thus the free movement of labour that is the most prized advantage of being in the EU—more even than membership of the single market. Yet Theresa May, the prime minister, has indicated that controlling immigration from Europe will be central to her approach to Brexit. And on January 10th Jeremy Corbyn, Labour’s leader, said he was no longer “wedded” to the free movement of EU workers. Even if those Europeans already employed in Britain are granted the right to stay after Brexit, as seems likely, the flow of new migrants could reduce to a trickle in just a couple of years. Bosses are therefore being compelled to rethink their employment practices. The options before them are not enticing, but they could change the way that Britain does business.

The employers’ main problem is a tight labour market. Employment is at a record high. Most studies agree that, in general, EU migrants have not displaced many British workers, nor put much downward pressure on wages. Rather, Britain’s relatively fast-growing economy has created millions of jobs. Equally, argues Jonathan Wadsworth of the London School of Economics, immigrants’ need for housing, food and transport has created more opportunities. So it is idle to presume that there is an army of frustrated, unemployed British workers ready to pick up the spanners of departing Polish plumbers.

Still, this does not mean that businesses cannot do more to recruit in Britain. Take road haulage. Hauliers already face a shortage of drivers. With the 13% fall in the value of the pound since the referendum, a good number of Polish drivers have not bothered to return to Britain after the Christmas break. In this sense, argues Mr Semple, Brexit has come early. So his organisation is trying to rebrand the industry to attract school-leavers. Driving a lorry was seen as dull, smelly and underpaid; now, apparently, it’s an IT-driven essential service.

Another option is to widen Britons’ participation in the labour market. The Resolution Foundation, a think-tank, estimates that a further 2.6m people, including the elderly and disabled, could join the workforce by 2020. The question is how to tempt them in. Higher pay could help: the minimum wage is due to rise to £9 per hour by 2020. Yet businesses may struggle to foot these extra costs. From April any firm with an annual wage bill of more than £3m will face a new “apprenticeship levy”. Businesses are also grappling with a new requirement automatically to enroll employees in pension schemes. An idea floated by the immigration minister on January 11th, to charge businesses £1,000 a year for every skilled EU worker that they employ post-Brexit, got a cool reception and was hastily withdrawn.

An alternative would be to invest in labour-saving technology. Some Brexiteers see this as a bonus of leaving the EU: deprived of cheap labour, companies would be forced to become more efficient, and Britain’s low rates of productivity would improve. Ms Beck, for example, says that Brexit is speeding up her plans to phase in automated minibars at the Royal Lancaster. The ordinary sort take many man-hours to check and restock, whereas automated ones have sensors that tell reception when a guest is raiding the brandy. The Agriculture and Horticulture Development Board, a quango helping farmers to modernise, is funding experiments in automated broccoli-harvesting. Brexit has given such tests an added urgency.

Yet there are limits to how easily manpower can be replaced by machines. Broccoli is pretty robust, but picking soft fruit like raspberries will probably have to be done by hand for the foreseeable future. So farmers are hoping that, if free movement does come to an end, the government will reinstitute the Seasonal Agricultural Workers Scheme, abolished in 2013. Ministers have dropped hints that such visa schemes could be established in farming and other industries. At least, maybe.

If they are not, and if recruiting Britons or robots to do the work turns out to be too difficult or expensive, firms have another option: to up sticks and move to another country with a good supply of labour. The hotel business, by its nature, can’t do this. But industries such as food manufacturing could. If Britain’s firms cannot import enough workers, the country may simply export their jobs.