When Hong Kong math teacher Jessica was freed from jail last year, following her arrest during the territory's massive pro-democracy protests, she decided it was time to leave her home city and head abroad.

The 28-year-old is among thousands of Hong Kongers who have recently moved to Britain to build new lives following Beijing's crackdown on dissent in the former British colony, which returned to Chinese rule in 1997.

With Britain crying out for teachers, Jessica was confident she could quickly resume her career, but schools have repeatedly turned her down because she has not provided background checks from the Hong Kong police.