LONDON • Ms Silvia Luis, from Portugal, is thinking of attending university in Scotland.
Ms Sandra Martinsone, a Latvian, said she might apply for citizenship or buy property.
Ms Julie Miquerol, from France, has sped up her plans to open a start-up company in Spain.
They, like some 1.3 million citizens between the ages of 18 and 35 from other European Union countries who live in Britain, are hedging their bets and pondering strategies in case Britain votes to leave the EU on June 23.
For years, Britain's relatively vibrant economy has attracted a steady flow of young people fleeing a lack of opportunity in their home countries on the Continent. London, in particular, is full of young Europeans.
The so-called Brexit debate has left some feeling fearful, frustrated and even angry.
"Maybe I'm too much of a drama queen, but I feel that it's such a bold statement against immigrants and Europeans," said Mr Alejandro Macias, 31, a Spaniard who lived in Germany before moving to Britain to work in an audience research company.
If Britain votes out, three-quarters of citizens from other EU countries who are working in the country would not meet current visa requirements for overseas workers, according to a report by the Migration Observatory at Oxford University.
The impact would be greatest for workers in agriculture and the hospitality industry, it said.
There are concerns that London, in particular, would suffer if the flow of skilled immigrants fell. About one million EU citizens from other countries work in London, a city of more than 8.5 million people.
Entrepreneurs, many of whom flocked to London because of the relative ease of creating start-ups, said they were concerned that they may have to put their business plans on hold.
Some said they might leave if Britain rejected the EU, while others were scrambling to apply for British citizenship or get full-time employment before the June deadline.
Mr Russell King, an academic who researches young European immigrants in Britain, said there was a "high level of concern among young people" over the vote.
"They are very active in taking measures to make sure they will be able to stay, to actively prove their worth to the UK and to the economy," he said.
NEW YORK TIMES