Ros Atkins On… Four reasons why the relationship between the UK and China is strained

This week, Yang Tengbo was identified as a 50-year-old Chinese businessman and suspected spy banned from the UK.

This has prompted questions about an issue many British governments are grappling with: the UK's relationship with China.

As the British Chancellor prepares to visit China in the new year, BBC analysis editor Ros Atkins examines how relations between the two countries became so tense.