Brexit protesters insult Boris Johnson and chant pro-EU songsAlastair Campbell

London's Polish Embassy has been inundated with calls from UK citizens asking about acquiring Polish passports. Queries have risen by 10,000% since the Brexit vote. "We've had a lot of calls and email enquiries from people enquiring about the possibilities of getting Polish passports," a Polish Embassy spokeswoman said.

"Since the referendum we've had 280 emails and around 700 phone calls, so it's been a big number." She added: "Before, we were generally getting 10 enquiries in total each month."

There are concerns about fake citizenship being sold through unscrupulous companies, the Polish Embassy warned. "We don't support these kinds of companies who help to get people passports, anyone wanting to apply for Polish citizenship or passports must be eligible and apply through the official channels."

Automatic citizenship is awarded to anyone who has at least one Polish parent. However, it is not usually given to those whose only connection to the country is through a spouse.

The embassy spokeswoman told the Evening Standard: "It's generally British citizens who are married to Polish people and have children who would like to know how to get a Polish passport and citizenship. The other people have Polish relatives or Polish grandparents who are eligible and have decided to apply."

Britons are worried about travelling freely around Europe in the wake of the EU referendum. There were also rises in internet searches for "dual citizenship" following UK voters opting to leave the EU. A Guardian website survey received over 1,200 replies from European citizens, many of whom were in the process of changing nationality or citizenship.

Freedom of movement will continue in the UK until the Article 50 process of the Lisbon Treaty has been completed, which takes at least two years. Major worries about the Brexit aftermath are the end of fast-track EU-only lines at passport control; tighter restrictions on studying and doing business; cash transfers between member states and higher taxes on foreign property ownership.